Correlation between the Interface Width and the Adhesion Strength of Copper Films Deposited on Ion-Etched Carbon Steel Substrates by Varying the Bias Voltage
1) The document examines how applying a negative bias voltage to carbon steel substrates during copper film deposition via magnetron sputtering affects the adhesion strength and interface width between the film and substrate.
2) Adhesion strength, measured via scratch testing, increased with higher bias voltage. The critical load reached 18.5g at -600V bias compared to 9.5g for an unbiased substrate.
3) Interface width, measured by Auger electron spectroscopy, also increased with higher bias voltage. The width was 335nm at -600V bias versus 180nm for an unbiased substrate.
4) The results suggest that bias voltage promotes diffusion and mixing at the interface, widening it. This, along
To ensure good adhesion between a 200 nm thick silicon dioxide layer and a 4.5 μm thick hardcoat polymeric coating, a better understanding of mechanisms of adhesion at this interface is needed. To reach this purpose, focus is placed on two axes: characterizing mechanical properties of materials composing the system and in parallel, finding an applicable and effective method to quantify adhesion. Small dimension of SiO2 thin film makes it challenging to accurately characterize it. Hence the use of both nano-indentation and AFM to attempt assessment of SiO2 thin film elastic modulus Ef; taking into account limitations and uncertainty associated with each technique. Elastic modulus of SiO2 thin film determined by nano-indentation is roughly 50 GPa on a wafer substrate and 15 GPa on a lens substrate. As for AFM, modulus measured is approximately 56 GPa on a wafer substrate and 22 GPa on a lens substrate. This highlights significant influence of substrate for both techniques. Impact on mechanical properties between SiO2 thin films under different intrinsic stresses was also investigated. Results suggest that higher density of SiO2 thin film leads to higher elastic modulus.
To quantify adhesion, micro-tensile and micro-compression tests were performed. Micro-tensile experiments give ultimate shear strengths of hardcoat-substrate interface ranging from 9 to 14 MPa. Values of energy release rates of SiO2 / Hardcoat, range from 0.1 J/m² to 0.5 J/m², depending on moduli values found on wafer or lens substrate.
Annealing and Microstructural Characterization of Tin-Oxide Based Thick Film ...Anis Rahman
Abstract. The sheet resistance of tin oxide based thick-film resistors exhibits two regions of temperature dependence,
described by hopping (23°C-200°C) and diffusion mechanisms (200°C-350°C), respectively.
Annealing these samples causes the sheet resistance to increase in both regions. In the post-annealed samples,
the hopping conduction range is extended by 50°C (23°C-250°C) while the hopping parameter, To, is decreased by
more than 50%. The activation energy of diffusion (0.60 eV) is the same for both pre- and post annealed samples, but
the magnitude of resistance in the diffusion controlled region is increased significantly as a result of annealing. These
changes are explained in terms of a net decrease in the concentration of tin ions in the glass matrix. From a careful
microstructural study it was found that a conduction path composed of tin-oxide grains or their clusters in contact
with each other does not exist in the present system. HREM micrographs showed the presence of nanocrystalline
tin-oxide particles in the glass phase separating the tin-oxide grain clusters. Estimated average separation between
the nanocrystals in 4 nm, consistent with a variable-range hopping conduction via the dissolved tin ions in the glass
matrix.
To ensure good adhesion between a 200 nm thick silicon dioxide layer and a 4.5 μm thick hardcoat polymeric coating, a better understanding of mechanisms of adhesion at this interface is needed. To reach this purpose, focus is placed on two axes: characterizing mechanical properties of materials composing the system and in parallel, finding an applicable and effective method to quantify adhesion. Small dimension of SiO2 thin film makes it challenging to accurately characterize it. Hence the use of both nano-indentation and AFM to attempt assessment of SiO2 thin film elastic modulus Ef; taking into account limitations and uncertainty associated with each technique. Elastic modulus of SiO2 thin film determined by nano-indentation is roughly 50 GPa on a wafer substrate and 15 GPa on a lens substrate. As for AFM, modulus measured is approximately 56 GPa on a wafer substrate and 22 GPa on a lens substrate. This highlights significant influence of substrate for both techniques. Impact on mechanical properties between SiO2 thin films under different intrinsic stresses was also investigated. Results suggest that higher density of SiO2 thin film leads to higher elastic modulus.
To quantify adhesion, micro-tensile and micro-compression tests were performed. Micro-tensile experiments give ultimate shear strengths of hardcoat-substrate interface ranging from 9 to 14 MPa. Values of energy release rates of SiO2 / Hardcoat, range from 0.1 J/m² to 0.5 J/m², depending on moduli values found on wafer or lens substrate.
Annealing and Microstructural Characterization of Tin-Oxide Based Thick Film ...Anis Rahman
Abstract. The sheet resistance of tin oxide based thick-film resistors exhibits two regions of temperature dependence,
described by hopping (23°C-200°C) and diffusion mechanisms (200°C-350°C), respectively.
Annealing these samples causes the sheet resistance to increase in both regions. In the post-annealed samples,
the hopping conduction range is extended by 50°C (23°C-250°C) while the hopping parameter, To, is decreased by
more than 50%. The activation energy of diffusion (0.60 eV) is the same for both pre- and post annealed samples, but
the magnitude of resistance in the diffusion controlled region is increased significantly as a result of annealing. These
changes are explained in terms of a net decrease in the concentration of tin ions in the glass matrix. From a careful
microstructural study it was found that a conduction path composed of tin-oxide grains or their clusters in contact
with each other does not exist in the present system. HREM micrographs showed the presence of nanocrystalline
tin-oxide particles in the glass phase separating the tin-oxide grain clusters. Estimated average separation between
the nanocrystals in 4 nm, consistent with a variable-range hopping conduction via the dissolved tin ions in the glass
matrix.
Fabrication and Characterization of PPS /40%GF/nano-CaCo3 Hybrid CompositesIJMER
International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
International Journal of Modern Engineering Research (IJMER) covers all the fields of engineering and science: Electrical Engineering, Mechanical Engineering, Civil Engineering, Chemical Engineering, Computer Engineering, Agricultural Engineering, Aerospace Engineering, Thermodynamics, Structural Engineering, Control Engineering, Robotics, Mechatronics, Fluid Mechanics, Nanotechnology, Simulators, Web-based Learning, Remote Laboratories, Engineering Design Methods, Education Research, Students' Satisfaction and Motivation, Global Projects, and Assessment…. And many more.
Evaluation of Damage by the Reliability of the Traction Test on Polymer Test ...inventy
In recent decades, polymers have undergone a remarkable historical development and their use has been greatly imposed by gradually dethroning most of the secular materials. These polymer materials have always distinguished themselves by their simple shaping and inexpensive price, their versatility, lightness, and chemical stability but despite their massive use in everyday life as well as in advanced technologies. Generally, these materials still not understood which requires a thorough knowledge of their chemical, physical, rheological and mechanical properties. This paper, we study the mechanical behavior of an amorphous polymer: Acrylonitrile Butadiene Styrene “ABS” by means of uniaxial tensile testing on pierced test pieces with different notch lengths ranging between 1 to 14mm.The proposed approach consists in analyzing the evolution of the global geometry of the obtained strain curves by taking into account the zones and characteristic points of these curves as well as the effect of the damage on the mechanical behavior of the polymer ABS, in order to visualize the evolution of the damage by a static model
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Ahmed ibrahim razooqi...corrosion conduct of austenitic stainless steel 316 l...ahmed Ibrahim
Corrosion conduct of Austenitic stainless steel 316L subjected
to surface treatment.
Abstract. The influence of low temperature liquid nitriding as a surface heat treatment analogy
with laser peening treatment at the various of throbs on pitting corrosion of the “AISI 316L
Austenitic stainless steel” is investigated in this paper. According to typical ASTM (G71-31) a
number of corrosion examination samples are equipped with the measurements of (15 * 15 * 3)
mm which distributed into the many groups. Three sets were exposed to liquid nit riding
process at temperatures of (500, 400, 300) Co for one hour. The specimens (without coating)
were exposed to a number of the throbs (1,2,3) by laser peening. Microstructure varia tions,
compression residual stress, hardness, were inspected in this work. The corrosion and its
variables (potential cell, current density) were also evaluated using the potential stat
examination and applying the Tafel method using saltwater solution (3.5% NaCl). Tafle
equation was used to compute the corrosion degree. The results revealed that the liquid
nitriding participated to raise the corrosion rate at (500) Co, compared to the original metal
because of chromium nitride and also leaser peening participated to the increase in the
corrosion rate due to plastic deformation which led to the heterogeneity in the microstructure
but liquid nitriding at temperature (400) oC gave the best result where it was closer to the parent
metal’s, also laser peening at one throb showed the lower corrosion rate.
Effect of PVD Coating and Carburizing on Wear Characteristics of Low Carbon S...IJERD Editor
Wear is a relative cyclic motion with small amplitude which occurs between two oscillating
surfaces, depending upon the loading conditions, material properties and environment. Surface Engineering
such as surface treatment, coating and surface modifications are employed to minimise the friction and improve
wear resistance of steel. In this work the low carbon steel substrate is coated with Al2O3 by using physical
vapour deposition process and the other sampling material is heat treated by carburizing process. In the present
study, the wear resistance of heat treated and coated steels were evaluated through the pin-on-disk using
variable loads and wear is measured by the wear track width and wear graphs are shown for coated material and
heat treated material. Finally, the comparison is concluded by observing the variations in wear characteristics
between the two samples. Furthermore morphological study of wear is made for in-depth analysis
Fabrication and Characterization of PPS /40%GF/nano-CaCo3 Hybrid CompositesIJMER
International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
International Journal of Modern Engineering Research (IJMER) covers all the fields of engineering and science: Electrical Engineering, Mechanical Engineering, Civil Engineering, Chemical Engineering, Computer Engineering, Agricultural Engineering, Aerospace Engineering, Thermodynamics, Structural Engineering, Control Engineering, Robotics, Mechatronics, Fluid Mechanics, Nanotechnology, Simulators, Web-based Learning, Remote Laboratories, Engineering Design Methods, Education Research, Students' Satisfaction and Motivation, Global Projects, and Assessment…. And many more.
Evaluation of Damage by the Reliability of the Traction Test on Polymer Test ...inventy
In recent decades, polymers have undergone a remarkable historical development and their use has been greatly imposed by gradually dethroning most of the secular materials. These polymer materials have always distinguished themselves by their simple shaping and inexpensive price, their versatility, lightness, and chemical stability but despite their massive use in everyday life as well as in advanced technologies. Generally, these materials still not understood which requires a thorough knowledge of their chemical, physical, rheological and mechanical properties. This paper, we study the mechanical behavior of an amorphous polymer: Acrylonitrile Butadiene Styrene “ABS” by means of uniaxial tensile testing on pierced test pieces with different notch lengths ranging between 1 to 14mm.The proposed approach consists in analyzing the evolution of the global geometry of the obtained strain curves by taking into account the zones and characteristic points of these curves as well as the effect of the damage on the mechanical behavior of the polymer ABS, in order to visualize the evolution of the damage by a static model
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Similar to Correlation between the Interface Width and the Adhesion Strength of Copper Films Deposited on Ion-Etched Carbon Steel Substrates by Varying the Bias Voltage
Ahmed ibrahim razooqi...corrosion conduct of austenitic stainless steel 316 l...ahmed Ibrahim
Corrosion conduct of Austenitic stainless steel 316L subjected
to surface treatment.
Abstract. The influence of low temperature liquid nitriding as a surface heat treatment analogy
with laser peening treatment at the various of throbs on pitting corrosion of the “AISI 316L
Austenitic stainless steel” is investigated in this paper. According to typical ASTM (G71-31) a
number of corrosion examination samples are equipped with the measurements of (15 * 15 * 3)
mm which distributed into the many groups. Three sets were exposed to liquid nit riding
process at temperatures of (500, 400, 300) Co for one hour. The specimens (without coating)
were exposed to a number of the throbs (1,2,3) by laser peening. Microstructure varia tions,
compression residual stress, hardness, were inspected in this work. The corrosion and its
variables (potential cell, current density) were also evaluated using the potential stat
examination and applying the Tafel method using saltwater solution (3.5% NaCl). Tafle
equation was used to compute the corrosion degree. The results revealed that the liquid
nitriding participated to raise the corrosion rate at (500) Co, compared to the original metal
because of chromium nitride and also leaser peening participated to the increase in the
corrosion rate due to plastic deformation which led to the heterogeneity in the microstructure
but liquid nitriding at temperature (400) oC gave the best result where it was closer to the parent
metal’s, also laser peening at one throb showed the lower corrosion rate.
Effect of PVD Coating and Carburizing on Wear Characteristics of Low Carbon S...IJERD Editor
Wear is a relative cyclic motion with small amplitude which occurs between two oscillating
surfaces, depending upon the loading conditions, material properties and environment. Surface Engineering
such as surface treatment, coating and surface modifications are employed to minimise the friction and improve
wear resistance of steel. In this work the low carbon steel substrate is coated with Al2O3 by using physical
vapour deposition process and the other sampling material is heat treated by carburizing process. In the present
study, the wear resistance of heat treated and coated steels were evaluated through the pin-on-disk using
variable loads and wear is measured by the wear track width and wear graphs are shown for coated material and
heat treated material. Finally, the comparison is concluded by observing the variations in wear characteristics
between the two samples. Furthermore morphological study of wear is made for in-depth analysis
Influence of Thickness on Electrical and Structural Properties of Zinc Oxide ...paperpublications3
Abstract: Zinc Oxide (ZnO) thin films were prepared on corning (7059) glass substrates at a thickness of 75.5 and 130.5nm by RF sputtering technique. The deposition was carried out at room temperature after which the samples were annealed in open air at 1500C. The electrical and structural properties of these films were studied. The electrical properties of the films were monitored by four-point probe method while the structural properties were studied by X-ray diffraction (XRD). It was found that the electrical resistance of the films decreases with increase in the thickness of the films. The XRD analysis of the films showed that the films have a peak located at 〖34.31^0-34.35〗^0with hkl (002). Other parameters calculated include the stress ( ) and the grain size (D).
Creep is defined as the plastic deformation under sustain load. Creep strain depends
primarily on the duration of sustained loading. It has been widely acknowledged that creep of
concrete is greatly influenced by the surrounding ambient. Creep induces the deflection of the
structural member with time. Hence the study on creep of concrete is necessary to prevent failure. A
concrete cylinder is casted for two different grades and the load of 40% of its compressive strength
is applied constantly. Creep is measured with time. A time - dependent creep is provided in a graph
showing its variation.
Surface Morphological and Electrical Properties of Sputtered Tio2 Thin FilmsIOSR Journals
Titanium dioxide films were formed on quartz and crystalline p-Si (100) substrates by DC reactive magnetron sputtering method. Pure titanium target was sputtered at a constant oxygen partial pressure of 5x10-2 Pa, and at different sputtering powers in the range 80 – 200 W. The as-deposited films were annealed in air for 1 hour at 1023 K. The deposited films were characterized by studying the surface morphology by atomic force microscopy (AFM), electrical and dielectric properties from current-voltage and capacitance-voltage measurements. Atomic force micrographs of the films showed that the Rrms and Ra increased with the increase of sputter power from 80 to 200 W. The leakage current density was increased by increasing the sputtering power.
surface characteristics and electrochemical impedance investigation of spark-...mohammad fazel
In this study, the surface characteristic of oxide films on Ti-6Al-4V alloy formed by an anodic oxidation treatment at potentials higher than the breakdown voltage was evaluated.
Experimental Study of the Flexural Behaviour of Damaged RC Beams Strengthened...IJERA Editor
This paper presents the flexural behaviour of basalt fiber reinforced polymer (BFRP) strengthened reinforced concrete (RC) beams. For flexural strengthening of reinforced concrete beams, total twenty-two beams were cast and tested over an effective span of 900 mm up to failure of the beam under two-point loading. The beams were designed as under-reinforced beams. The beams were bonded with BFRP sheets in single layer and double layers in the bending moment region at the bottom face of the beam. Out of the twenty-two beams two beams were control beams and remaining beams were strengthened after being damaged for various degrees of damage (0 %, 70 %, 80 %, 90% and 100 %). The experimental results show that the beams strengthened show high load carrying capacity.
Ultra smooth and lattice relaxed zn o thin films [eid]Eid Elsayed
thin film from ZnO
Similar to Correlation between the Interface Width and the Adhesion Strength of Copper Films Deposited on Ion-Etched Carbon Steel Substrates by Varying the Bias Voltage (20)
Nonclassical Properties of Even and Odd Semi-Coherent StatesIOSRJAP
Even and odd semi-coherent states have been introduced. Some of the nonclasscial properties of the states are studied in terms of the quadrature squeezing as well as sub-Poissonian photon statistics. The Husimi– Kano Q-function and the phase distribution in the framework of Pegg and Barnett formalism, are also discussed.
Spherical and Cylindrical Ion Acoustic Solitary Waves in Electron-Positron-Io...IOSRJAP
The propagation of cylindrical and spherical ion acoustic solitary waves in a plasma system consisting of ions, electrons and positrons are investigated. The electrons and positrons are assumed to be following the nonextensive distribution popularly known as Tsallis distribution. The standard nonlinear equation i.e. Korteweg de-Vries (KdV) equation has been solved numerically using suitable mathematical transformations. The effect of nonextensivity (q) and nonplanar geometry on the amplitudes and width of ion acoustic potential structures have been studied numerically. A transition from negative to positive potential structures have been observed for the planar as well as nonplanar geometries for lower values of q in the range −1 < 푞 < 0. Soliton amplitude is maximum for spherical waves and is minimum and for planar waves while it lies in between the two for cylindrical waves. The present investigation may help us in understanding the study of cylindrical and spherical solitary waves in astrophysical plasmas.
Nuclear Material Verification Based on MCNP and ISOCSTM Techniques for Safegu...IOSRJAP
Recently, Mathematical techniques such as Monte Carlo and ISOCSTM software are being increasingly employed in the absolute efficiency calibration of gamma ray detector. Monte Carlo simulations and Canberra ISOCSTM software bring the possibility to establish absolute efficiency curve for desired energy range based on numerical simulation, with use of known or guessed geometry and chemical composition, of measured item. Broad-energy germanium (BEGe) detector was employed to perform the NDA measurements to five standard reference nuclear material (NBS, SNM-969). MC calculations were performed to calculate some factors (attenuation, geometry and efficiency) which affect the uranium isotope mass estimation. 235U and 238U masses are calculated based on MCNPX modeling calibration and also upon spectra analysis using ISOCSTM Calibration Software. The obtained results from the two different efficiency calibration methods were compared with each other and with the declared value for each sample. The obtained results are in agreements with the declared values within the estimated relative accuracy (ranges between -2.81 to 1.83%). The obtained results indicate that the techniques could be applied for the purposes of NM verification and characterization where closely matching NM standards are not available.
Growth, characterization, and antibacterial studies of L-Lysine single crysta...IOSRJAP
Single crystals of L-lysine added Potassium Bromide were grown by slow evaporation technique at room temperature. The crystalline nature of the grown crystal wasconfirmed using powder X-ray diffraction technique. Single crystal X-ray diffraction patterns were recorded for the structural conformation and it was found to be cubic. The UV –VIS- NIR Spectrum of the grown crystals shows less optical absorption and good transmittance in the entire visible region enabling its use in optical applications. Vickers micro hardness test was carried out to analyze the mechanical property of the grown L- lysine potassium Bromide single crystal. Thermo gravimetric analysis proved that the crystal is stable up to 600ºC. The frequency and temperature dependence of dielectric constant (εr), dielectric loss (tan δ) were also measured. The grown crystal was evaluated for its biological efficacy and found to exhibit anti bacterial activities against some select bacterial strains.
Controlled Quantum Teleportation via Four Particle Asymmetric Entangled State IOSRJAP
A general scheme for controlled teleportation of an arbitrary single-qubit state with four-qubit asymmetric state is proposed. In this scheme, the sender performs Bell measurement on his particle, the two controllers and the receiver perform joint unitary operation on the rest particles. Finally, the receiver can reconstruct the single particle by introducing an auxiliary particle, he first does unitary transformation on his particle and the auxiliary particle, then performs a Von Neumann measurement on the auxiliary particle. Thus the scheme can be realized in certain probability.
Low Cost Synthesis of Single Walled Carbon Nanotubes from Coal Tar Using Arc ...IOSRJAP
There are various methods such as arc discharge, laser ablation, chemical vapour deposition (CVD), template-directed synthesis for the growth of CNTs in the presence of catalyst particles. The production of carbon nanotubes in large quantities is possible with inexpensive coal as the starting carbon source by the arc discharge technique. It is found that a large amount of carbon nanotubes of good quality can be obtained in the cathode deposits in which carbon nanotubes are present in nest-like bundles. For more than two decades, now, there has been extensive research on the production of carbon nanotubes (CNT) and optimization of its manufacture for the industrial applications. It is believed that they are the strong enough but most flexible materials known to mankind. They have potential to take part in new nanofabricated materials. It is known that, carbon nanotubes could behave as the ultimate one-dimensional material with remarkable mechanical properties. Moreover, carbon nanotubes exhibit strong electrical and thermal conducting properties. This paper primarily concentrates on the optimising such parameters related to the mass production of the product. It has been shown through Simplex process that based on the cost of the SWNT obtained by the arc discharge technique, the voltage and the current should lie in the range of 30 - 42 V and 49 - 66 A respectively. Any combination above the given values will lead to a power consumption cost beyond the final product cost, in turn leading to infeasibility of the process. Strong expectations exist for future use of carbon nanotubes as composite materials in a large number of industries. Production cost and control of the purity and properties of such materials will influence the impacts nanotubes on the chemical, computer and construction industries. Coal properties in this case are also important. Weak bonds and mineral matter in the coal play an important role in the formation of the nanotubes
Pion Form Factor Contribution in Vacuum Polarization corrections for 1s energ...IOSRJAP
The 1푠 energy level vacuum polarization correctionsof pionic hydrogen atom induced by a potential including form factor are compared with those obtained by using pion point potential. Without form factor of nucleus and pion the correction increases very slowly for low Z atoms and increases fastly for higher Z. The finite size of the nucleus increases the correction with Z in case of exponential distribution, while in case of Gaussian distribution the increase is lower. For Fermi distribution there is a fast increase at low values of Z and faslty decreases with higher values of Z. The effect of form factor of pion on the correction is very clear for low Z nuclei and then becomes nearly constant for higher values Z.
To the Issue of Reconciling Quantum Mechanics and General RelativityIOSRJAP
The notion of gravitational radiation as a radiation of the same level as the electromagnetic radiation is based on theoretically proved and experimentally confirmed fact of existence of stationary states of an electron in its gravitational field characterized by the gravitational constant K = 1042G (G is the Newtonian gravitational constant) and unrecoverable space-time curvature Λ. If the numerical values of K 5.11031 Nm2 kg-2 and =4.41029 m -2 , there is a spectrum of stationary states of the electron in its own gravitational field (0.511 MeV ... 0.681 MeV).Adjusting according to the known mechanisms of broadening does not disclose the broadening of the registered portion of the emission spectrum of the micropinch. It indicates the presence of an additional mechanism of broadening the registered portion of the spectrum of the characteristic radiation due to the contribution of the excited states of electrons in their own gravitational field. The energy spectrum of the electron in its own gravitational field and the energy spectra of multielectron atoms are such that there is a resonance of these spectra. As obvious, the consequence of such resonant interaction is appearance, including new lines, of electromagnetic transitions not associated with atomic transitions. The manuscript is the review of previously published papers cited in the references.
Study Of Structural, Morphological And Optical Properties Of Pure CdO And Ag:...IOSRJAP
Pure and Ag doped CdO thin films were prepared by sol-gel technique with spin coating method on glass substrates, Ag:CdO doped with relatively high concentration Ag (2.5%, 5%, 10% and 15%) to obtain changes in structural, Optical And Morphological properties of Ag:CdO doped thin films at fixed annealing temperature (300◦ C), the results Shows changes in structural properties at (111) plane due to fixed annealing temperature, and decreasing in direct energy gap, and show changes in roughness average.
Equivalent Thicknesses of Lead and Fly ash Geopolymer with Addition of Barium...IOSRJAP
This study aims to fabricate radiation protection shields using fly ash with barium Sulphate. Different thickness of fly ash geopolymer with 15% of barium sulphate was constructed, and different energies of X-ray ranged from 80 kVp - 120 kVp were used to assessment the attenuation ability of Lead and fly ash geopolymer with barium Sulphate shields. Different thicknesses of fly ash based shields are investigated to determine the equivalent thicknesses of fly ash geopolymer with barium sulphate which provide the same attenuation by Lead shields. The results exhibited that 5 cm of fly ash geopolymer with barium Sulphate equivalent 1 mm of Lead in attenuating of incident X-ray. Whereas 1 cm of fly ash geopolymer with barium sulphate equivalent 0.25 mm of Lead shield at various X-ray energy (80 kVp -120 kVp).
Energy Release Rate for Fiber Reinforced Polymer CompositeIOSRJAP
An experimental investigation using drag-out tensile test to calculate the interfacial shear strength for different embedded lengths and radius of Kevlar -49, carbon and ultra high polyethylene fibers reinforced epoxy matrix , the energy release rate calculated by using Nairn model . The energy release rate increase as the embedded fiber length increase and also for fiber radius for perfect adhesion , for specimens with bubbles at interface which seems to reduce the fracture toughness the energy release rate be less than specimens with perfect adhesion , the thermal stress and friction forces were included in the energy release rate in Kevlar-49 and carbon reinforced epoxy the interfacial shear force due to friction part decrease while in solid ultra high polyethylene the interfacial shear force due to friction part increase.
Disaggregation of Annual to daily Streamflows: A lineardeterministic methodIOSRJAP
In this study, a linear deterministic methodis applied to disaggregate streamflow from annual to daily data inunregulated stations located on the Kızılırmak river in Turkey. To disaggregate annual streamflows to the daily flow at the target station (TS), annual counterparts at the source station (SS) were identified depending on the minimum error criteria that is estimated based on the volume of three-year time window. Then, daily streamflow indexes at SS were calculated to disaggregate annual to daily streamflow at TS through the process. The same steps are replicated to disaggregate monthly streamflow to the daily flow for the purpose of comparison between the two methods. The results are well represents daily streamflow at two methods inquiry comparing to observe data, and also maintain the time series statistical characteristics and mass equilibrium. The comparative results suggest that the monthly to daily disaggregation method perform better than annual to the daily disaggregation method. The daily streamflow generated in this study can be used in the future research for water resources planning and management.
Studies of Dielectric Constant, Dielectric Loss, Loss Tangent and Dielectric ...IOSRJAP
The arrangement of waves or radiation in order of increasing frequencies is called electromagnetic spectrum. Frequency of microwave region is 300MHz to 300GHz. Corresponding wavelength is in between 1mm to 100cm. Here by using a microwave bench dielectric properties such as dielectric constant, dielectric loss, loss tangent and dielectric relaxationtime of Dichlorobenzene, Bromobenzene and Nitrobenzene in different temperatures at X band frequrency are measured. Gopalakrishnan method is used for determination of relaxation time. Here real (€/ ) and imaginary (€")parts of complex dielectric constant( €*) were determined in the 3cm microwave region for different concentration of Dichlorobenzene, Bromobenzene and Nitrobenzene in Cyclohaxene at temperatures 240C, 330C and 410C .The measurement were made at a frequency of 9.98GHz. From the study of relaxation time polarity of above three compounds are studied. From the structural point of view the most interesting Dielectric Relaxation is that involving orientation polarization which depends on the internal structure of molecules and on the molecular arrangement or structure of the dielectric. Dielectric relaxation is the lag in dipole orientation behind an alternating electric field. From the study it is found that relaxation time of these solute is more in Cyclohexane then in Benzene. This behavour can be explained from the fact that Cyclohexane has more internal friction than Benzene.
Development of Ni-doped Yttria stabilized Zirconia composite for SOFC applica...IOSRJAP
Ni-doped Yttria stabilized Zirconia (NiO/YSZ) has been synthesized using low cost combustion process from an aqueous solution containing ZrO(NO3)2.6H2O, Y(NO3)3.6H2O, Ni(NO3)2.6H2O and urea. Pellets were sintered at 13500C for 5 hours and its sintered density is estimated to be of 95%. Sintered pellets were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM) & X-ray photoelectron spectroscopy (XPS) techniques. From the XRD analysis, as grown powder of NiO/YSZ showed nano-crystalline behavior with homogeneous mixture of YSZ and NiO phases. However sintered powder showed µ-size dense grain growth. Temperature and frequency dependent dielectric properties are corroborated with the conduction mechanism. Both dielectric constant (K) and loss (tan δ) are increased sharply at high temperature region, which is expected to be the onset of dipolar relaxation phenomena due to the presence of oxygen vacancies. A mixed conductivity involving ionic conduction in the high temperature range and electronic conduction in the low temperature range was observed. The decrease in K and tan δ with increase in frequency at a given temperature suggests the dynamic interaction of oxygen vacancies & oxide ion pairs.
A relationship between mass as a geometric concept and motion associated with a closed curve in spacetime (a notion taken from differential geometry) is investigated. We show that the 4-dimensional exterior Schwarzschild solution of the General Theory of Relativity can be mapped to a 4-dimensional Euclidean spacetime manifold. As a consequence of this mapping, the quantity M in the exterior Schwarzschild solution which is usually attributed to a massive central object is shown to correspond to a geometric property of spacetime. An additional outcome of this analysis is the discovery that, because M is a property of spacetime geometry, an anisotropy with respect to its spacetime components measured in a Minkowski tangent space defined with respect to a spacetime event P by an observer O who is stationary with respect to the spacetime event P, may be a sensitive measure of an anisotropic cosmic accelerated expansion. The presence of anisotropy in the cosmic accelerated expansion may contribute to the reason that there are currently two prevailing measured estimates of this quantity
Evaluation of the mass attenuation coefficient and Effective Atomic Number of...IOSRJAP
The potential of the Eremurus spp. root as a binder in Rhizophora-Eremurus spp. particleboard mammography phantom had been approved. In this study, the potential of Eremurus spp. as a phantom material has been investigated. The effective atomic number of the Eremurus spp. was calculated as an important parameter in the low energy range. Also, the mass attenuation coefficient of the Eremurus spp. root was measured in the 16.63 keV – 25.30 keV photon energy as a mammography range. Although, the effective atomic number of the Eremurus spp. was near to that of tissue, the mass attenuation of the Eremurus spp. root was not found close to those of breast tissue and water phantom. The results show that the Eremurus spp. root can be used just as a binder in phantom and it cannot be as a main phantom material.
Structural Stability of Nano-Crystalline Aluminum-Glass CompositesIOSRJAP
Effects of particle size of the material in nanometer on solid state, structural properties AluminumGlass based samples are reported in this study. The particle size of 25µm was used for both Aluminum and Glass powders respectively. The samples were prepared in powdered form of various Al-Glass proportions. The weight of Aluminum ranges between 20 – 60 percent in the composites. Results showed from X-ray diffraction analyses that Aluminum addition and the determined particle size greatly influence the structural stability of the samples. It was revealed that samples were structurally stable in the range of Aluminum composition and the observed size of crystals, measured Width at Middle of Maximum Height and structural parameters were found in nanometers. The Al-Glass materials were noted to crystallize with FCC and BCC lattice structures.
Higher-Order Squeezing of a Generic Quadratically-Coupled Optomechanical SystemIOSRJAP
Using short-time dynamics and analytical solution of Heisenberg equation of motion for the Hamiltonian of quadratically-coupled optomechanical system for different field modes, we have investigated the existence of higher-order single mode squeezing, sum squeezing and difference squeezing in absence of driving and dissipation. Depth of squeezing increases with order number for higher-order single mode squeezing. Squeezing factor exhibits a series of revival-collapse phenomena for single mode, which becomes more pronounced as order number increases. In case of sum squeezing amounts of squeezing is greater than single mode higher-order squeezing (n = 2). It is also greater than from difference squeezing for same set of interaction parameters. Sum squeezing is prominently better for extracting information regarding squeezing.
Dielectric, Electric and Thermal Behavior of La3+ doped Co-Zn NanoferriteIOSRJAP
Dielectric, Electric and Thermal properties of rare earth La3+ material doped in Co0.5Zn0.5 Lax Fe(2- x)O4 (where x=0.025, 0.050, 0.075, 0.100, 0.125) reaction nanocrystalline ferrites were synthesized by sol-gel auto combustion method. The electric, dielectric constant and Thermal properties were investigated. The dielectric constants and dielectric loss of the samples was observed between the 100Hz and 5 MHz. The resistivities of the prepared samples were measured from 0 Volt to 550 Volts at the constant temperature 2000C using the Two Probe method. The Thermal properties were characterized by Thermo Gravimetric and Differential Thermal Analysis (TGDTA).
PLC Based Instrumentation of Closed Loop Gas System for RPC DetectorsIOSRJAP
The INO experiment is a mega-science project and will have RPC detectors as an active element. It will be instrumented with about 28,800 RPC detectors. These active detectors use a gas mixture of R134a (95.2%), Isobutane (4.5%) and SF6 (0.3%). Due to large number of RPC detectors, the total gas required is of the order of 200 M 3 ; therefore a Closed Loop gas recirculation System (CLS) is mandatory. The prototype CLS system for 12 such RPCs has been developed using PLC (Programmable Logical Controllers) and associated peripheral input and output devices. This CLS is based on pneumatic parameters; hence many pressure sensors are used in process control and operation. Several simple CLS are developed by the team of Alpha pneumatics. The paper high lights the instrumentation of the CLS, which is in operation at TIFR and a few results are presented
Sachpazis:Terzaghi Bearing Capacity Estimation in simple terms with Calculati...Dr.Costas Sachpazis
Terzaghi's soil bearing capacity theory, developed by Karl Terzaghi, is a fundamental principle in geotechnical engineering used to determine the bearing capacity of shallow foundations. This theory provides a method to calculate the ultimate bearing capacity of soil, which is the maximum load per unit area that the soil can support without undergoing shear failure. The Calculation HTML Code included.
Water scarcity is the lack of fresh water resources to meet the standard water demand. There are two type of water scarcity. One is physical. The other is economic water scarcity.
Student information management system project report ii.pdfKamal Acharya
Our project explains about the student management. This project mainly explains the various actions related to student details. This project shows some ease in adding, editing and deleting the student details. It also provides a less time consuming process for viewing, adding, editing and deleting the marks of the students.
Hierarchical Digital Twin of a Naval Power SystemKerry Sado
A hierarchical digital twin of a Naval DC power system has been developed and experimentally verified. Similar to other state-of-the-art digital twins, this technology creates a digital replica of the physical system executed in real-time or faster, which can modify hardware controls. However, its advantage stems from distributing computational efforts by utilizing a hierarchical structure composed of lower-level digital twin blocks and a higher-level system digital twin. Each digital twin block is associated with a physical subsystem of the hardware and communicates with a singular system digital twin, which creates a system-level response. By extracting information from each level of the hierarchy, power system controls of the hardware were reconfigured autonomously. This hierarchical digital twin development offers several advantages over other digital twins, particularly in the field of naval power systems. The hierarchical structure allows for greater computational efficiency and scalability while the ability to autonomously reconfigure hardware controls offers increased flexibility and responsiveness. The hierarchical decomposition and models utilized were well aligned with the physical twin, as indicated by the maximum deviations between the developed digital twin hierarchy and the hardware.
Overview of the fundamental roles in Hydropower generation and the components involved in wider Electrical Engineering.
This paper presents the design and construction of hydroelectric dams from the hydrologist’s survey of the valley before construction, all aspects and involved disciplines, fluid dynamics, structural engineering, generation and mains frequency regulation to the very transmission of power through the network in the United Kingdom.
Author: Robbie Edward Sayers
Collaborators and co editors: Charlie Sims and Connor Healey.
(C) 2024 Robbie E. Sayers
Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)MdTanvirMahtab2
This presentation is about the working procedure of Shahjalal Fertilizer Company Limited (SFCL). A Govt. owned Company of Bangladesh Chemical Industries Corporation under Ministry of Industries.
CFD Simulation of By-pass Flow in a HRSG module by R&R Consult.pptxR&R Consult
CFD analysis is incredibly effective at solving mysteries and improving the performance of complex systems!
Here's a great example: At a large natural gas-fired power plant, where they use waste heat to generate steam and energy, they were puzzled that their boiler wasn't producing as much steam as expected.
R&R and Tetra Engineering Group Inc. were asked to solve the issue with reduced steam production.
An inspection had shown that a significant amount of hot flue gas was bypassing the boiler tubes, where the heat was supposed to be transferred.
R&R Consult conducted a CFD analysis, which revealed that 6.3% of the flue gas was bypassing the boiler tubes without transferring heat. The analysis also showed that the flue gas was instead being directed along the sides of the boiler and between the modules that were supposed to capture the heat. This was the cause of the reduced performance.
Based on our results, Tetra Engineering installed covering plates to reduce the bypass flow. This improved the boiler's performance and increased electricity production.
It is always satisfying when we can help solve complex challenges like this. Do your systems also need a check-up or optimization? Give us a call!
Work done in cooperation with James Malloy and David Moelling from Tetra Engineering.
More examples of our work https://www.r-r-consult.dk/en/cases-en/
Planning Of Procurement o different goods and services
Correlation between the Interface Width and the Adhesion Strength of Copper Films Deposited on Ion-Etched Carbon Steel Substrates by Varying the Bias Voltage
1. IOSR Journal of Applied Physics (IOSR-JAP)
e-ISSN: 2278-4861.Volume 9, Issue 1 Ver. I (Jan. – Feb. 2017), PP 82-89
www.iosrjournals.org
DOI: 10.9790/4861-0901018289 www.iosrjournals.org 82 | Page
Correlation between the Interface Width and the Adhesion
Strength of Copper Films Deposited on Ion-Etched
Carbon Steel Substrates by Varying the Bias Voltage
Abousoufiane Ouis1,2,*
, Kamal Touileb1
, Rachid Djoudjou1
,
Abdulhakim Okleh1
1
Mechanical Engineering Department, Prince Sattam bin Abdulaziz University, Al Kharj, Saudi Arabia
2
Laboratoire de Sciences des Surfaces et Interfaces en Mécanique, ISITEM, Université de Nantes,France
Abstract: The present study has been conducted in order to determine the influence of negative bias voltage
applied to substrate on adhesion of copper films deposited on carbon steel substrates. The adhesion strength
has been evaluated by the scratch test. Coatings were deposited by a DC magnetron sputtering system. The
substrates were firstly mechanically polished and then ion-etched by argon ions prior to deposition. Adhesion
was found to increase with the bias voltage. The critical load had a value of 9.5 g for an unbiased substrate and
reached 18.5 g for a bias voltage of 600 V. Equally important, the interface width, measured using Auger
electron spectroscopy, increased as a function of the bias voltage. The width of the interface is related to the
time of ion milling in the Auger spectrometer. The size of this width is obtained from the Auger elemental depth
profiles through measuring the depth of the interface coating/substrate. The width had a value of 335 min with a
bias of 600 V whereas it didn't exceed 180 min when the substrate was unbiased. Therefore, the effect of the
bias voltage was to expand the interface because of the diffusion phenomenon and physical mixing of materials
at the interface. Moreover, the critical load increased with the increase of the interface width.
Keywords: DC sputtering, Ar ion bombardment, Bias voltage, Adhesion, Auger electron spectroscopy.
I. Introduction
In the industrial production of coatings, one of the important problem to surmount is the maximization
of coating to substrate adhesion strength. To do this, many processes are used such as ion bombardment of the
substrate surface, heating of specimens, deposition of an intermediate layer, application of a substrate bias
voltage and others. Application of a substrate bias voltage on the substrate during the film growth process has
been identified as a very promising technology for producing well adherent coatings. It can greatly modify the
mechanical properties particularly the adhesion, tribological properties, morphology, crystallographic
composition of a wide variety of film-substrate. Seeman published a paper on the knowledge and understanding
of the biasing technique [1] that had a two-fold purpose: First, to provide persons in science and industry
interested in thin film technology with a basic understanding of the theory, mechanisms and techniques of bias
sputtering; and second, to point out the versatility of this technique by illustrating its use in practical
applications. It is noted that the theory and mechanisms of the biasing action are very similar to those seen in the
basic ion sputtering concept. For instance, in a study of TiAlLaN films deposited on WC-Co and on silicon
substrates [2], Hao Du et al. found that by increasing the bias voltage from 30 to 70 V, titanium concentration
increased from 34.51 to 38.05% and nitrogen atomic content remained almost constant. However, aluminum
and lanthanum concentrations decreased from 14.39 to 12.37% and from 1.51 to 0.73% respectively. This
variation has been explained by a phenomenon of ionization and the backscattering of deposited elements. The
grains of the films changed from equiaxial to columnar structure and the grain size changed from 36.44 to 36.33
nm due to the alteration of film surface energy under the bias voltages. Moreover, the mechanical properties of
the films notably changed. For instance, the increase in the critical load of the adhesion scratch test is from 75 to
84 N, for the hardness is from 29.48 to 38.27 GPa and for the elastic modulus is from 449.15 to 667.35 GPa.
Deviaet al. reported their results [3] related to TiAlN coatings deposited on AISI O 1 tool steel using a triode
magnetron sputtering system by varying the bias voltage from 40 to 150 V. The titanium content decreased
from 32 to 30 at.% and the aluminum content increased slightly from 25 to 28 at.%, while the nitrogen content
was found to remain constant. The transformation of the crystallographic structure of the film from preferred {1
1 1} to random {2 0 0} oriented with increasing the bias voltage was due to the reduced average ion energy.
Moreover, the grain size of the film increased from 51.3 to 96.3 nm leading to a decreasing of the hardness from
32 to 19 GPa. The film thickness showed an inversely proportional relationship with the bias voltage as it
decreased from 1.875 to 1.295m.Although this technique tends to produce denser films. In other work of
Cr2O3 films deposited by arc ion plating on AISI 304 stainless steel substrates [4], Wang et al. found that with
increasing the bias voltage from 0 V, the hardness increased gradually from 27.6 GPa to reach the highest value
2. Correlation between the Interface Width and the Adhesion Strength of Copper Films Deposited on
DOI: 10.9790/4861-0901018289 www.iosrjournals.org 83 | Page
of about 32.2 GPa at 100 V, and then sharply decreased to 25.4 GPa at 250 V. Moreover, the critical load of
adhesion scratch test first increased from about 29 N to the maximum of 46.7 N when the bias changed from 0
to 100 V and then decreased gradually to about 32 N at a bias voltage of 250 V. The wear testing also
revealed that the bias voltage modified the friction coefficient of film. The origin of these phenomena was
attributed to the microstructure evolution and variation of defect density in the films induced by the negative
bias voltage increase. Kovacet al. investigated the influence of substrate bias voltage on the properties of
sputtered aluminum-scandium thin sheets deposited on steel sheets by a DC magnetron sputtering unit [5]. The
results showed that the bias voltages caused a decrease in the deposition rate due to the resputtering of the
surface atoms. When the negative bias voltage varied from 0 to 250 V, the film morphology changed from a fine
to an irregular crystalline structure. Moreover, the micro-hardness of the sheets showed a monotonically
increase from about 150 HV for an unbiased substrate to about 635 HV for a bias voltage of – 250 V. In the
same range of bias voltage, the increase of the applied bias resulted in an augmentation of the free surface
roughness. This rise was relatively limited for small bias voltage but increased dramatically for values above –
150 V. On other hand, inert gas ions or other ion species with high, medium, and low energies have been used,
before or during film deposition process, to induce adhesion enhancement between deposited films and
substrates. The main effects of ions bombardment by argon ions could be summarized by the oxides layer
removal and a roughness creation on the substrate surface, and the substrate temperature increase. Donnelly and
Kornblit [6] have reviewed the field of plasma etching in a long review article entitled "Plasma etching:
Yesterday, today, and tomorrow". They presented its history, different categories, equipments, evolution,
mechanisms and applications. Nevertheless, the choice of the technique for evaluating the adhesion of thin films
on their substrates remains a major issue. Many techniques of measuring the adhesion have been developed and
evaluated [7]. The well established "scratch test" using a hemispherical diamond stylus, loaded tangentially to
the plane of the surface offers a high degree of usability and reproducibility [8].
In this work, the influence of a negative bias voltage applied to the substrate on the adhesion strength
coating-substrate was explored. The films of pure copper were fabricated by a DC magnetron sputtering system.
The substrates were made of E24 carbon steel. Before the deposition process, the substrate surfaces were treated
by argon ions etching. Consequently, the oxides layer at the substrate surface was removed and, an increase of
temperature and roughness of the substrate were generated. The bias voltage that was applied during all the film
growth was varied from 0 to 600 V. The attention was focused on the correlation between the interface
film/substrate width and the adhesion strength. The adhesion scratch test was used to evaluate the adhesion.
Whereas, the physicochemical nature of the interface and the inter-diffusion phenomenon between copper film
and steel substrate were assessed through Auger electron spectroscopy depth profiles. The obtained results
revealed that the interface width was an increasing function of the bias voltage. Moreover, critical load of the
scratch test increased with the increase of the interface width. These observations suggested that the bias voltage
had effects on one hand of diffusion and mixing of the materials at the interface, and on other hand of increasing
of the substrate temperature. Consequently, the latter effects contributed positively to the adhesion enhancement
of the film to the substrate.
II. Experimental Details
2.1. Substrate preparation
Common E24 carbon steel was used as substrate in this study. Chemical composition of this material is
listed in Table 1. The substrates were cut into pieces with sizes of 15×15×2 mm and their surface preparation
involved a sequential hand grinding with emery abrasive paper grades 600, 800 and 1200. Subsequently, a
polishing with diamond paste (particle sizes 6.0 and 1.0 m) was performed in order to obtain a mirror-like
finished substrate. After a cleaning procedure in ultrasonic baths of acetone and methanol, successively for
about 15 minutes for each, the substrate was rinsed in distilled water and finally dried under a stream of heated
air. Then, the substrate was immediately introduced in the deposition chamber.
Table 1.Chemical composition of E24 carbon steel
Chemical elements %, by mass
C (max) 0.17
P (max) 0.045
S (max) 0.045
Mn (max) 1.40
Fe balance
2.2. Coating deposition
The pure copper films were deposited by a DC magnetron sputtering system. When the sample was
introduced in the vacuum chamber, the chamber was first evacuated by a rotary vane pump to ≈1 Pa and then
pumped down by a diffusion pump to reach a base pressure of (5-7)10-4
Pa. The argon gas was leaked to the
3. Correlation between the Interface Width and the Adhesion Strength of Copper Films Deposited on
DOI: 10.9790/4861-0901018289 www.iosrjournals.org 84 | Page
chamber through a needle valve. The used deposition parameters are pressure of 1 Pa, cathodic voltage of 560 V
and current intensity of 1.8 A corresponding of a power density of 11.6 W.cm-2
and during all the processes, a
bias voltage was applied to the substrate by using an RF power supply. So, three series of specimens were
produced and analyzed with negative bias voltages of 0, 300 and 600 V. Nevertheless, all the samples received
before deposition process an in situ ion bombardment etching treatment with argon ions. The experimental
conditions of ion bombardment etching that were obtained in a previous study [9] represent the optimal
conditions giving the higher critical load in the adhesion scratch test namely argon pressure of 10 Pa, cathodic
voltage of 600 V and ion etching time of 10 min. When the ion etching was performed, the pressure in the
vacuum chamber was adjusted to the desired pressure, the bias voltage was immediately applied to the substrate
and the film deposition process started. However, the specimens were kept for about 3 min between the end of
the ion etching and the beginning of the deposition. As the application of a bias voltage causes an ion
bombardment of the film surface which causes a resputtering of the surface atoms and thus decreases the
deposition rate, the sputtering time was varied so that the film thickness was kept in a reasonable range of 200
nm. The detailed parameters used for the fabrication of these samples are listed in Table 2.
Table 2. Detailed parameters for pure copper films fabricated by DC magnetron sputtering technique
Parameters Value
Base pressure (Pa) (5-7) 10-4
Working pressure (Pa) 1
Deposition DC cathodic voltage (V) 560
Deposition current intensity (A) 1.8
Deposition energy density (W.cm-2
) 11.6
Ar ion bombardement pressure (Pa) 10
Ar ion bombardement voltage (V) 600
Ar ion bombardement time (min) 10
RF bias voltage (V) 0, –300, –600
Film thickness (nm) 200
2.3. Measurement of the critical load
Adhesion of the coating on the substrates was assessed by the adhesion scratch test. The principle of
the test consists of moving a loaded stylus with small weights and visually analyzing the scratch track. The
stylus is made of diamond with a tip radius of 17 m and mounted on a beam. To perform a scratching, first of
all the sample was positioned and fixed in a substrate-holder that was an x-y table. A DC motor allowed the
movement of the table in the x-direction and, for a given value of the load, a scratch was obtained. In our
experiments, we adopted scratches of about 5 mm long and a constant scratch speed of 3.7 mm.min–1
. On the
same sample, a series of parallel scratches was manually performed by moving the table in y-direction using of a
micrometer screw. From one series of scratches to the other, the load was increased by a discrete value of the
load until the coating/substrate adhesion failure occurred. The shapes of the scratch tracks were analyzed by an
optical microscope and micrographs were taken. For a given load, a series of at least three scratches were
realized and each channel was separately examined by optical inspection. Thus, the adhesion failure was
estimated by a mean critical load.
III. Results and Discussion
3.1. Adhesion measurement
The surface treatment by argon ions bombardment prior to deposition process that has major effects of
removing oxides layer, creating a roughness on the substrate surface and elevating the substrate temperature
plays an important role in the adhesion improvement [10-13]. For instance, Lim et al. [14] studied the effects of
the surface roughness of 96% pure Al2O3 substrates on the adhesion of 99.99% pure copper films. Trapezium
rule of calculation in 2D model for estimated total surface area has been introduced. The various roughness
grades have been analyzed using Atomic Force Microscopy and the adhesion strength has been evaluated with
pull strength measurements. With rougher surface, the adhesive strength is higher due to the larger contact area
at the interface. This effect can account for an adhesive strength increment of more than 50%. Additionally,
Lahmar et al. [15] who investigated the adhesion of the similar previous coating-substrate by the scratch test
have drawn almost similar conclusions. The substrates were ion etched before deposition by Ar ions. The
increase in the scratch test critical load was caused by a better adhesion of the coating to its substrate resulting
from a widening of the interface region. On other hand, the argon ion etching eliminated the contamination
(oxygen and carbon) and created vacancies and microcavities on the surface substrate, and produced an
important contact surface coating-substrate allowing a good anchoring of the coating on its substrate. In our
work, as all samples received the same surface treatment by argon ions etching prior to deposition.This
treatment has no effect on the variation of the critical load as a function of the bias voltage. Moreover, the bias
voltage has effects, among others, of physical mixing of materials in the interfacial domain, increasing of the
diffusion and improving the deposited film quality (greater densification). Hence, these effects of the ion etching
4. Correlation between the Interface Width and the Adhesion Strength of Copper Films Deposited on
DOI: 10.9790/4861-0901018289 www.iosrjournals.org 85 | Page
and the bias voltage, when combined, give an enhancement of the adherence greater than this one obtained if
only one of the effect is applied. Table 3 shows the variation of the mean critical load in the adhesion scratch
test as a function of the substrate negative bias voltage. The critical load increases as a function of the bias
voltage. It has a value of about 9.5 g for an unbiased substrate and reaches a value of about 18.5 g for a bias
voltage of 600 V. Hence, the amplification factor is of about 2. The literature review reveals that the effects of
the bias voltage variation on the adhesion of films to their substrates can be mainly attributed to some factors
such as hardness, structure, chemical composition of the coating and internal stress in the coating generated by
the bias voltage as well as to the deposition parameters. Thus, prior to deposition of a-C:H films, Wazumiet al.
[16] sputter-cleaned the silicon wafer by Ar plasma applying a negative DC voltage of 2.0 kV for 30 min.
Afterward, films prepared at different bias voltages presented an improvement of the adhesion due to produced
low compressive stress. Other results have been reported by Shi et al. [17] when investigating the adhesion
properties of the nano-scaled CrTiAlN multilayer coatings deposited on Mg alloy substrates by unbalanced
magnetron sputtering. The results of the scratch test with a progressive load indicated that the adhesion force of
the coating was strongly affected by the negative substrate bias voltage. They revealed that the critical load was
only about 3.75 N at 40 V and reached 10 N at 50 V. However, the critical load value decreased with the
increase in bias voltage and the reason for this behavior could be cited to the generation of excess compressive
stresses due to the bombardment by high energy ions, and the consequent detrimental of the coating adhesion.
Hence, the authors indicated that the adhesion property of the coatings is subject essentially to the chemical
composition and deposition parameters. Comparable results have been reported by Valeriniet al. [18] in the case
of ZrN films sputtered on tungsten carbide substrates. Beside fracture energy, microhardness and internal stress,
Müller and Fromm investigated the adhesion strength of TiN coatings on HSS substrates as a function of the
negative bias voltage [10]. The critical load, increased from 9 to 17 N with increasing bias voltage from 0 to
120 V. The hardness values were constant from 0 to 20 V. Between 20 and 40 V they steeply increased
from 1910 to 2600 HV but for higher bias voltage they did not change any more. The different behavior of the
scratch test and the hardness values were caused by the change of the structure of the TiN coating due to
application of a bias voltage. Argon ions accelerated in the field of the bias voltage hit the substrate surface and
enhanced the mobility of the surface atoms. This had the consequence that the open, porous, columnar coating
structure was converted to a denser film. Nevertheless, the change in the coating structure increased the values
by a factor of two in a similar way as the hardness values. The authors concluded that the critical load was
obviously more affected by the change of the coating hardness than by the change of the adhesion strength.
Table 3. Critical load of adhesion scratch test as a function of the substrate bias voltage. Data of the copper
films prepared using negative bias voltage from Ouiset al. [9]
Substrate bias voltage (V) 0 300 600
Mean critical load (g) ±0.5 g 9.5 12.0 18.5
The results of the adhesion scratch test were analyzed by an optical microscope. Figure 1shows
micrographs of the scratch tracks obtained for substrates argon ion etched before deposition and coated with
copper applying a 300 V bias voltages during deposition process. Under these conditions for such specimens,
the mean critical load is about 12.0 g. Figure 1(a) is related to an applied load of 11 g. The scratch channel has a
uniform appearance revealing that the coating remains in a good adherence to the substrate. So, this load is less
than the critical load. In Figure 1(b), the load is 12 g and small film loosening starts to appear along the scratch
track edges. Hence, this load can be approved as the critical load. Whereas, applying a load of 15 g, scratch
track shows clearly that the film is totally removed under the stylus as shown in Figure 1(c). Consequently, the
applied load is much greater than the critical load and it is an evidence that the adhesion loss is complete.
(a) (b) (c)
Figure 1. Optical microscopy micrographsof scratch track of the scratch test of copper films deposited
on ion etched substrates with an applying bias voltage of 300 V.The mean critical load was ≈12 g. The applied
stylus load was (a) 11 g, (b) 12 g and (c) 15 g.
5. Correlation between the Interface Width and the Adhesion Strength of Copper Films Deposited on
DOI: 10.9790/4861-0901018289 www.iosrjournals.org 86 | Page
3.2. Auger electron spectroscopy
Auger electron spectroscopy (AES) was used to determine the chemical elements present in the
coating, in the interface coating/substrate and in the substrate as well as to measure the interface width. An
elemental depth profile was derived from a series of Auger spectra taken at different ion milling time by plotting
the peak-to-peak heights of the principal Auger lines as a function of ion milling time. According to the obtained
AES results, the main chemical elements detected are copper, iron, oxygen and/or carbon. Figure 2 is related to
samples ion bombardment etched before depositions under the optimal conditions of ion etching before
deposition. Figure 2(a) corresponds to an unbiased substrate. Figures 2(b)and 2(c) correspond to substrates
where negative bias voltages of 300 and 600 V are respectively applied during deposition. For all substrates
prepared with or without bias voltage, a superficial contamination has been observed at the coating surface. This
contamination comes from the formation of a superficial layer during the transfer of the sample in the
atmosphere from the deposition chamber to the Auger spectrometer. This generated layer is removed by the first
ion millings in the AES spectrometer. Moreover, an obtained and expected result is that for all the samples, the
oxygen is absent in the interface. When performing mechanical polishing of the substrates before their
introduction to the deposition chamber, an amorphous layer of oxides is generated on the substrate surface. This
layer is removed by the ion bombardment etching. Hence, the interface presents no contamination. In the case of
an unbiased sample (Figure 2(a)), the oxygen is completely absent however traces of carbon are present in the
interface and in the substrate. This presence is probably due to the carbon contained in the substrate
composition. In that case, it is important to remember that the samples were prepared from commercial quality
steel with a not perfectly uniform distribution of the constituent elements.
The AES depth profiles allowed us to measure the width of the interface for different applied bias
voltages. The interface begins to form when the iron starts to increase and the copper starts to decrease. Thus,
the interface is considered as finished when the iron remains constant and the copper disappears. Based on the
aforementioned considerations, the interface width is measured in minutes, corresponding of the ion milling
time in the AES spectrometer. As far as the effects of the bias voltage on the interface width and then on the
adhesion coating/substrate are considered, Figure 3 and 4 are plotted. Figure 3 presents the results of the
variation of the interface width as a function of the bias voltage. It is clear that when the bias increases, the
interface width increases. When the bias had values of 0, 300 and 600 V, the corresponding interface widths
were 180, 270 and 335 min respectively. It is evident that the interface is significantly more wide and more
diffuse for a biased substrate than for an unbiased substrate where the interface is more abrupt. Therefore,
application of a bias voltage on the substrate has a positive effect in the enlargement of the interface due to
diffusion phenomenon and intermixing of materials at the interface.
According to the results of the adhesion scratch test (cf. Table 3), Figure 4 presents the relationship
between the mean critical load and the interface width. The mean critical load is an increasing function of the
interface width. When the interface width has a value of 180 min le critical load is 9.5 g for an unbiased
substrate. However, when the interface width increases to a value of 335 min the critical load becomes 18.5 g
for an applied bias voltage of 600 V. The critical load is significantly influenced by the application of a bias
voltage. Hence, the latter parameter has an important contribution in the adhesion enhancement of the coating to
its substrate.
(a)
6. Correlation between the Interface Width and the Adhesion Strength of Copper Films Deposited on
DOI: 10.9790/4861-0901018289 www.iosrjournals.org 87 | Page
(b)
(c)
Figure 2. Auger depth profiles obtained for copper films onto E24 carbon steel substrate. Before
deposition, the substrate was ion etched at 600 V and 10 Pa and 10 min and, during deposition, a substrate bias
voltage was applied of (a) 0 V, (b)300 V and (c) 600V.
Figure 3. Variation of the interface width measured in the Auger spectra as a function of the bias voltage.
7. Correlation between the Interface Width and the Adhesion Strength of Copper Films Deposited on
DOI: 10.9790/4861-0901018289 www.iosrjournals.org 88 | Page
Figure 4.Variation of the critical load as a function of the interface width.
Our results are in good agreement with those obtained by Tang et al.[19] when studying the adhesion
strength of TiN films synthesized on GCr15-bearing steel using plasma immersion ion implantation and
deposition. Prior to the deposition process, the samples were treated by Ar+ sputtering. They found that the
critical load in the adhesion scratch test increased from 1.80 to 2.89 N when the sputtering time varied from 0 to
30 min respectively. In addition, when the bias voltage was increased from 10 to 30 kV, the adhesion strength
raised from 2.37 to 14.6 N respectively. As the interface width was estimated by the nitrogen concentration in
the interface induced by the implantation voltage, the authors observed that high implantation voltage resulted in
a high implantation depth. For example, the critical load increased from 1.84 to 10.37 N when the nitrogen
implantation varied from 0 to 8 kV. Consequently, when the nitrogen concentration in the interface increased,
the interface width increased and the adhesion strength increased also. Regarding the materials intermixing
effects at the interface, Cheng et al. [20] investigated by a scratch test the adhesion enhancement of (Cu, Nb, Ti)
films deposited by evaporation on SiO2 at room temperature and at 300°C and using Ar ions bombardment to
various doses. The experimental results showed that the adhesion strength increased after bombardment at a
threshold dose and then saturated at higher doses in all pairs. The possible mechanism involved in this
phenomenon has been mainly attributed to the nuclear energy loss.The nuclear energy loss during ion beam
processing induces many defects in the solids such as vacancies, interstitials and their clusters, thermal spikes,
etc... inducing a layer of intermixing atoms at the interface coating/substrate. However in our study, a wide
range of factors, such microhardness and internal stress in the coating as well as film crystallography will affect
the values of the critical load when a bias voltage is used during the deposition process. Further investigation is
needed to explore the relationship between these factors and the scratch adhesion.
IV. Conclusions
Pure copper films were fabricated by a DC magnetron sputtering unit. Prior to deposition, the carbon
steel substrates were argon ion etched. Different negative bias voltages were applied on the substrates during the
deposition process. Critical load in the adhesion scratch test has been measured. Effects of the negative substrate
bias voltage on the interface width and on the critical load were studied. Auger electron spectroscopy (AES) has
been used to analyze the coating, the interface coating/substrate and the substrate. Results of this study allow to
draw the following conclusions:
1. During the transfer of the sample in the atmosphere from the deposition chamber to the Auger spectrometer,
the coating surface presents a contamination characterized by a layer of oxides. This layer is removed by
the first ion millings in the AES spectrometer.
2. The mechanical polishing of the substrates generates at the surface substrate an amorphous layer of oxides
and carbon. The optimal conditions of the ion bombardment are opted for etching the substrates before the
deposition process (argon pressure: 10 Pa, cathodic voltage: 600 V, ion etching time: 10 min). This ion
etching eliminates the amorphous layer and creates vacancies and microcavities that produces an important
contact surface coating-substrate allowing a good adhesion of the coating to the substrate.
3. The critical load is an increasing function of the bias voltage. It changes from a value of ≈9.5 g without bias
to ≈18.5 g at 600 V bias voltage. This variation could be explained by the effect of the increasing of
substrate temperature and by the mechanical anchoring of the coating to its substrate on the one hand (due
to ion etching) and by the diffusion and the materials mixing in the interfacial domain (due to the substrate
bias voltage) on the other hand.
8. Correlation between the Interface Width and the Adhesion Strength of Copper Films Deposited on
DOI: 10.9790/4861-0901018289 www.iosrjournals.org 89 | Page
4. The bias voltage has a noteworthy effect on the interface width enlargement. The interface width has a
value of 335 min for a bias of 600 V whereas it has only 180 min for an unbiased substrate. Thus, the
interface is wider (diffuse) for a biased substrate than for an unbiased one (abrupt). This phenomenon is
mainly due to the diffusion and intermixing of the materials in the interface. The temperature generated by
the bias voltage has also a contribution.
5. The critical load is an increasing function of the interface width. It reaches ≈18.5 g for an interface width of
335 min whereas it is ≈9.5 g for 180 min. The amplification factor is about 2. As a result, a strong
relationship exists between the interface width and the adhesion; the higher interface width, the better
adhesion.
Acknowledgements
The authors express their gratefulness to Dr. D. Roptin and Mr. J. P. Roche (EcoleCentrale de Nantes-
University of Nantes-France) for the Auger electron spectroscopy analyses.
References
[1] J.M. Seeman, Bias sputtering: its techniques and applications, Vacuum, 17(3), 1967, 129-137.
[2] H. Du, J. Xiong, H. Zhao, Y. Wu, W. Wan, L. Wang, Structure and properties of TiAlLaN films deposited at various bias voltages,
App. Surf. Sci.,292, 2014, 688-694.
[3] D.M. Devia, E. Restrepo-Parra, P. J. Arango, A. P. Tschiptschin, J. M. Velez, TiAlN coatings deposited by triode magnetron
sputtering varying the bias voltage, App. Sur. Sci., 257(14), 2011, 6181-6185.
[4] T-G. Wang, D. Jeong, Y. Liu, Q. Wang, S. Iyengar, S. Melin, K.H. Kim, Study on nanocrystalline Cr2O3 films deposited by arc ion
plating: II. Mechanical and tribological properties, Surf. Coat. Technol., 206, 2012, 2638-2644.
[5] J. Kovac, H-R Stock, H-W Zoch, Influence of substrate bias voltage on the properties of sputtered aluminum-scandium thin sheets,
J. Surf. Eng. Mat. Adv. Tech., 2, 2012, 115-119.
[6] V.M. Donnelly, A. Kornblit, Plasma etching: Yesterday, today, and tomorrow, J. Vac. Sci. Technol., A 31, 050825, 2013,doi:
10.1116/1.4819316 (48 pages).
[7] J. Valli, A review of adhesion test methods for thin hard coatings, J. Vac. Sci. Technol., A 4, 1986, 3007-3014.
[8] T.R. Hull, J.S. Colligon, A.E. Hill, Measurement of thin film adhesion, Vacuum, 37(3-4), 1987, 327-330.
[9] A. Ouis, M. Cailler, Effects of substrate bias voltage on adhesion of DC magnetron-sputtered copper films on E24 carbon steel:
investigations by Auger electron spectroscopy, J. Adhesion Sci. Technol., 27(21), 2013, 2367-2386.
[10] D. Müller, E. Fromm, Mechanical properties and adhesion strength of TiN and Al coatings on HSS, steel, aluminium and copper
characterized by four testing Methods, Thin Solid Films, 270, 1995, 411-416.
[11] M. Cailler, A. Ouis, P.J. Schultz, P.J. Simpson, The adhesion strength of copper thin-films to E24 carbon steel: effects of substrate
surface ion bombardment etching, J. Adhesion Sci. Technol., 7(2), 1993, 141-157.
[12] K-D. Bouzakis, S. Makrimallakis, G. Katirtzoglou, G. Skordaris, S. Gerardis, E. Bouzakis, T. Leyendecker, S. Bolz, W. Koelker,
Adaption of graded Cr/CrN-interlayer thickness to cemented carbide substrates' roughness for improving the adhesion of HPPMS
PVD films and the cutting performance, Surf. Coat. Technol., 205(5), 2010, 1564-1570.
[13] F.H. Sun, Z.M. Zhang, M. Chen, H.S. Shen, Improvement of adhesive strength and surface roughness of diamond films on Co-
cemented tungsten carbide tools, Diamond Relat. Mater., 12(3-7), 2003, 711-718.
[14] J.D. Lim, Y.S.Y. Susan, R.M.W. Daniel, K.C. Leong, C.C. Wong, Surface roughness effect on copper–alumina adhesion,
Microelectron. Reliab.,53(9-11), 2013, 1548-1552.
[15] A. Lahmar, N. Hmina, Y. Scudeller, J.P. Bardon, Correlation between the adhesion and the thermal contact resistance: effects of
substrate surface ion bombardment etching, Thin Solid Films,325(1-2), 1998, 156-162.
[16] K. Wazumi, Y. Koga, A. Tanaka, Tribological properties of a-C:H films on Si substrate prepared by plasma CVD in pulse-biased
process, Diamond Relat. Mater.,12, 2003,1018-1023.
[17] Y. Shi, S. Long, S. Yang, F. Pan, Deposition of nano-scaled CrTiAlN multilayer coatings with different negative bias voltage on
Mg alloy by unbalanced magnetron sputtering, Vacuum, 84, 2010, 962-968.
[18] D. Valerini, M.A. Signore, L. Tapfer, E. Piscopiello, U. Galietti, A. Rizzo, Adhesion and wear of ZrN films sputtered on tungsten
carbide substrates, Thin Solid Films, 538, 2013, 42-47.
[19] B. Tang, Y. Wang, L. Wang, X. Wang, H. Liu, Y. Yu, T. Sun, Adhesion strength of TiN films synthesized on GCr15-bearing steel
using plasma immersion ion implantation and deposition, Surf. Coat. Technol., 186, 2010, 153-156.
[20] G. Cheng, S. Xu, D. Ye, Adhesion modification in (Cu, Nb, Ti)/SiO2 pairs by argon ion bombardment, Nucl. Instrum.
Methods:Beam Interactions with Materials and Atoms,135(1-4), 1998, 545-549.