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.
Synthesis of Cobalt ferrite by Solid Reaction Methodsank_sanjay
Cobalt ferrite nano-crystalline powder was synthesized from the powder mixture of cobalt carbonate and iron oxide by mixed oxide ceramic method. The effects of temperature of calcination as well as molar ratio of CoCO3/Fe2O3 on the phase structure, morphology and magnetic properties of the products were studied using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and vibrating sample magnetometer (VSM) techniques, respectively. The samples calcined at 800 and 900˚C consisted of cobalt ferrite, iron oxide and cobalt oxide. In the sample calcined at 1000˚C, the reaction was completed and single phase CoFe2O4 with a mean crystallite and particle sizes of 49 and 300 nm, respectively was obtained.
Photo-induced reduction of CO2 using a magnetically separable Ru-CoPc@TiO2@Si...Pawan Kumar
An efficient photo-induced reduction of CO2 using magnetically separable Ru-CoPc@TiO2@SiO2@Fe3O4
as a heterogeneous catalyst in which CoPc and Ru(bpy)2phene complexes were attached to a solid
support via covalent attachment under visible light is described. The as-synthesized catalyst was characterized
by a series of techniques including FTIR, UV-Vis, XRD, SEM, TEM, etc. and subsequently tested for
the photocatalytic reduction of carbon dioxide using triethylamine as a sacrificial donor and water as a
reaction medium. The developed photocatalyst exhibited a significantly higher catalytic activity to give a
methanol yield of 2570.78 μmol per g cat after 48 h.
Electrospun Nanofibers Reinforced Aluminium Matrix Composites, A Trial to Imp...IJAMSE Journal
A comparison between TiO2 nanofibers and carbon nanofibers as fibers reinforced metal matrix composites with respect to mechanical properties improvements have been made in this paper. Al and Mg have been chosen as metal matrices. The used carbon and ceramic nanofibers (Titanium Oxide) were successfully synthesized using electrospinning technique. Various weight percentage of calcined
electrospun TiO2 and carbon nanofibers (1, 3, 5 and 10%) were mixed with metal matrix and fabricated by route of powder metallurgy using High Frequency Induction heat Sintering (HFIHS). Mechanical properties of the sintered composites have been investigated. The manufactured pellets were tested for compression test, hardness and microstructures by the field emission scanning electron microscopes (FESEM), which reveals the homogeneous distribution of nanofibers in the Al/Mg matrices. In addition,
energy-dispersive X-ray spectroscopy (EDS) was employed to obtain the chemical analysis of each composite. The result shows that, the ultimate compressive strength increased to 415 MPa at 5% TiO2, which is 13.5% more than the pure Al. The hardness increased up to 64% in case of using the ceramic nanofibers as reinforcement. While using CNFs as reinforcement to the Al matrix deteriorates the
mechanical properties.
Studies of the Atomic and Crystalline Characteristics of Ceramic Oxide Nano P...albertdivis
In the present study, some transition metal oxides (Zinc oxide, iron oxide and copper oxide) which are widely used in the fabrication of electronic devices were selected and subjected to biofield treatment.
Synthesis of Cobalt ferrite by Solid Reaction Methodsank_sanjay
Cobalt ferrite nano-crystalline powder was synthesized from the powder mixture of cobalt carbonate and iron oxide by mixed oxide ceramic method. The effects of temperature of calcination as well as molar ratio of CoCO3/Fe2O3 on the phase structure, morphology and magnetic properties of the products were studied using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and vibrating sample magnetometer (VSM) techniques, respectively. The samples calcined at 800 and 900˚C consisted of cobalt ferrite, iron oxide and cobalt oxide. In the sample calcined at 1000˚C, the reaction was completed and single phase CoFe2O4 with a mean crystallite and particle sizes of 49 and 300 nm, respectively was obtained.
Photo-induced reduction of CO2 using a magnetically separable Ru-CoPc@TiO2@Si...Pawan Kumar
An efficient photo-induced reduction of CO2 using magnetically separable Ru-CoPc@TiO2@SiO2@Fe3O4
as a heterogeneous catalyst in which CoPc and Ru(bpy)2phene complexes were attached to a solid
support via covalent attachment under visible light is described. The as-synthesized catalyst was characterized
by a series of techniques including FTIR, UV-Vis, XRD, SEM, TEM, etc. and subsequently tested for
the photocatalytic reduction of carbon dioxide using triethylamine as a sacrificial donor and water as a
reaction medium. The developed photocatalyst exhibited a significantly higher catalytic activity to give a
methanol yield of 2570.78 μmol per g cat after 48 h.
Electrospun Nanofibers Reinforced Aluminium Matrix Composites, A Trial to Imp...IJAMSE Journal
A comparison between TiO2 nanofibers and carbon nanofibers as fibers reinforced metal matrix composites with respect to mechanical properties improvements have been made in this paper. Al and Mg have been chosen as metal matrices. The used carbon and ceramic nanofibers (Titanium Oxide) were successfully synthesized using electrospinning technique. Various weight percentage of calcined
electrospun TiO2 and carbon nanofibers (1, 3, 5 and 10%) were mixed with metal matrix and fabricated by route of powder metallurgy using High Frequency Induction heat Sintering (HFIHS). Mechanical properties of the sintered composites have been investigated. The manufactured pellets were tested for compression test, hardness and microstructures by the field emission scanning electron microscopes (FESEM), which reveals the homogeneous distribution of nanofibers in the Al/Mg matrices. In addition,
energy-dispersive X-ray spectroscopy (EDS) was employed to obtain the chemical analysis of each composite. The result shows that, the ultimate compressive strength increased to 415 MPa at 5% TiO2, which is 13.5% more than the pure Al. The hardness increased up to 64% in case of using the ceramic nanofibers as reinforcement. While using CNFs as reinforcement to the Al matrix deteriorates the
mechanical properties.
Studies of the Atomic and Crystalline Characteristics of Ceramic Oxide Nano P...albertdivis
In the present study, some transition metal oxides (Zinc oxide, iron oxide and copper oxide) which are widely used in the fabrication of electronic devices were selected and subjected to biofield treatment.
Studies of the Atomic and Crystalline Characteristics of Ceramic Oxide Nano P...Mahendra Kumar Trivedi
In the present study, some transition metal oxides (Zinc oxide, iron oxide and copper oxide) which are widely used in the fabrication of electronic devices were selected and subjected to biofield treatment.
Spectroscopic studies on Mn2+ ions doped Cadmium Aluminum Fluoro Lead Borate ...IJERA Editor
This article reports on optical properties of Mn2+ (0.5 mol%): 49.5 B2O3 - 10PbO - 30CdO -10AlF3 glasses.
Optical absorption spectrum of the manganese ions doped glass exhibits broad absorption band at 473 nm.
Photoluminescence spectrum of Mn2+ (0.5 mol %): 49.5B2O3- 30CdO – 10PbO - 10AlF3 glass has revealed a red
emission at 618 nm with an excitation wavelength 467 nm.
Preparation, Structure, and Characterization of Nd2mo2o9 fast Oxide Ion Condu...IJARIIT
The structure and ion conductivity of Nd2Mo2O9powders were synthesized by using Nd(NO2)3, MoO3, and aspartic acid (fuel) in assisted combustion method with heating at 550˚C for 6 hours. The thermal decomposition, phase identification, morphology, ionic conductivity of the samples were studied by TGA/DTA, XRD and SEM four probe D.C. method respectively. The formation of Nd2Mo2O9 was confirmed by FTIR studies. The synthesis and crystallization were followed by thermochemical techniques (TGA/DTA) studies. The synthesized materials showed reasonable ionic conductivity. These results indicate that assisted combustion method is a promising method to prepare nanocrystalline Nd2Mo2O9 for solid oxide fuel cell.
Synthesis and Characterisation of Copper Oxide nanoparticlesIOSR Journals
Cupric oxide (CuO) nanoparticles were prepared by the chemical route by calcinations at a higher temperature from 300oC to 400 oC. For the comparison transmission electron microscopy (TEM) and x-ray diffraction (XRD) measurements were made through JCPDS. There is good agreement between data produced by spectroscopy and the microscopic measurements.
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.
Synthesis and Study on Structural, Morphological and Magnetic properties of n...Editor IJCATR
Mn3O4 nanoparticles were prepared by co-precipitation method followed by annealing of samples at 300 °C for 2 hours. The
samples were characterized to find the structural, functional, optical, morphological, compositional and magnetic properties by PXRD,
FTIR, Micro-Raman, HRSEM, TEM, XPS, EDX and VSM respectively. Structural studies by PXRD indicate that the annealing has
strongly influenced the phase transition showing two coexisting phases of Mn2O3 and Mn3O4. Micro-Raman spectra showed the
presence of A1g mode of vibration corresponding to Mn3O4 phase. Magnetic studies of the as synthesized Mn3O4 nanoparticles depict
paramagnetic behavior at room temperature.
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.
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.
Preparation of lithium ferrite nanoparticles by high energy ball milling and ...IJERA Editor
Ferrites are ferrimagnetic ceramic materials with inherent useful electromagnetic properties. Of them, spinelstructured ferrites are promising materials for microwave device applications; stress/torsion sensors and energy storage applications like anode materials in lithium batteries, fuel cells, solar cells etc. Nanostructured spinels further have high and wide scope of potential applications. In the present study, two different types of varied sized ferrimagnetic lithium ferrite spinel nanoparticles prepared using chemical sol-gel auto-combustion method were chosen. The prepared spinel particles were heated at 300°C for 1h. After heating the powders were milled using a High Energy Ball Mill for 30 minutes to further grind the particles and then subjected to various characterizations. Structural characterization was done using X-Ray Diffraction Method (XRD). The study revealed the spinel structure of these samples. Structural parameter such as lattice constant was determined using XRD data and found that the lattice parameter agrees with the standard data. DLS study found the agglomerations of the nanoparticles. The synthesized nanospinel particles were also characterized by the UVVis Spectroscopy, the Fourier Transform Infrared Spectroscopy (FTIR). Finally the magnetic hysteresis properties were studied using a Vibrating Sample Magnetometer (VSM)
Spectroscopic and Physical Properties of Mn2+ spin probe in RO-P2O5-ZnO-Pb3O4...IJERA Editor
RO-P2O5-ZnO-Pb3O4 (R=Li, Na and K) glasses containing 0.1concentrations of MnO have been prepared. The structural, optical and physical properties of prepared glasses are studied by XRD, UV-Visible, EPR and FTIR techniques. The nature of local symmetry and structural information of the neighboring atoms of dopant ions (Mn2+) in the host matrix have been understood by evaluating the crystal field strength (Dq) and Racah (B & C) parameters. The combined analysis of optical absorption and EPR spectroscopy has indicated that the manganese ions exist in Mn2+ (in octahedral) local coordination sites. FTIR results showed that PO4 are the main structural unit of the glass system and the manganese ions are located in the glass matrix network.
International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
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.
Studies of the Atomic and Crystalline Characteristics of Ceramic Oxide Nano P...Mahendra Kumar Trivedi
In the present study, some transition metal oxides (Zinc oxide, iron oxide and copper oxide) which are widely used in the fabrication of electronic devices were selected and subjected to biofield treatment.
Spectroscopic studies on Mn2+ ions doped Cadmium Aluminum Fluoro Lead Borate ...IJERA Editor
This article reports on optical properties of Mn2+ (0.5 mol%): 49.5 B2O3 - 10PbO - 30CdO -10AlF3 glasses.
Optical absorption spectrum of the manganese ions doped glass exhibits broad absorption band at 473 nm.
Photoluminescence spectrum of Mn2+ (0.5 mol %): 49.5B2O3- 30CdO – 10PbO - 10AlF3 glass has revealed a red
emission at 618 nm with an excitation wavelength 467 nm.
Preparation, Structure, and Characterization of Nd2mo2o9 fast Oxide Ion Condu...IJARIIT
The structure and ion conductivity of Nd2Mo2O9powders were synthesized by using Nd(NO2)3, MoO3, and aspartic acid (fuel) in assisted combustion method with heating at 550˚C for 6 hours. The thermal decomposition, phase identification, morphology, ionic conductivity of the samples were studied by TGA/DTA, XRD and SEM four probe D.C. method respectively. The formation of Nd2Mo2O9 was confirmed by FTIR studies. The synthesis and crystallization were followed by thermochemical techniques (TGA/DTA) studies. The synthesized materials showed reasonable ionic conductivity. These results indicate that assisted combustion method is a promising method to prepare nanocrystalline Nd2Mo2O9 for solid oxide fuel cell.
Synthesis and Characterisation of Copper Oxide nanoparticlesIOSR Journals
Cupric oxide (CuO) nanoparticles were prepared by the chemical route by calcinations at a higher temperature from 300oC to 400 oC. For the comparison transmission electron microscopy (TEM) and x-ray diffraction (XRD) measurements were made through JCPDS. There is good agreement between data produced by spectroscopy and the microscopic measurements.
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.
Synthesis and Study on Structural, Morphological and Magnetic properties of n...Editor IJCATR
Mn3O4 nanoparticles were prepared by co-precipitation method followed by annealing of samples at 300 °C for 2 hours. The
samples were characterized to find the structural, functional, optical, morphological, compositional and magnetic properties by PXRD,
FTIR, Micro-Raman, HRSEM, TEM, XPS, EDX and VSM respectively. Structural studies by PXRD indicate that the annealing has
strongly influenced the phase transition showing two coexisting phases of Mn2O3 and Mn3O4. Micro-Raman spectra showed the
presence of A1g mode of vibration corresponding to Mn3O4 phase. Magnetic studies of the as synthesized Mn3O4 nanoparticles depict
paramagnetic behavior at room temperature.
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.
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.
Preparation of lithium ferrite nanoparticles by high energy ball milling and ...IJERA Editor
Ferrites are ferrimagnetic ceramic materials with inherent useful electromagnetic properties. Of them, spinelstructured ferrites are promising materials for microwave device applications; stress/torsion sensors and energy storage applications like anode materials in lithium batteries, fuel cells, solar cells etc. Nanostructured spinels further have high and wide scope of potential applications. In the present study, two different types of varied sized ferrimagnetic lithium ferrite spinel nanoparticles prepared using chemical sol-gel auto-combustion method were chosen. The prepared spinel particles were heated at 300°C for 1h. After heating the powders were milled using a High Energy Ball Mill for 30 minutes to further grind the particles and then subjected to various characterizations. Structural characterization was done using X-Ray Diffraction Method (XRD). The study revealed the spinel structure of these samples. Structural parameter such as lattice constant was determined using XRD data and found that the lattice parameter agrees with the standard data. DLS study found the agglomerations of the nanoparticles. The synthesized nanospinel particles were also characterized by the UVVis Spectroscopy, the Fourier Transform Infrared Spectroscopy (FTIR). Finally the magnetic hysteresis properties were studied using a Vibrating Sample Magnetometer (VSM)
Spectroscopic and Physical Properties of Mn2+ spin probe in RO-P2O5-ZnO-Pb3O4...IJERA Editor
RO-P2O5-ZnO-Pb3O4 (R=Li, Na and K) glasses containing 0.1concentrations of MnO have been prepared. The structural, optical and physical properties of prepared glasses are studied by XRD, UV-Visible, EPR and FTIR techniques. The nature of local symmetry and structural information of the neighboring atoms of dopant ions (Mn2+) in the host matrix have been understood by evaluating the crystal field strength (Dq) and Racah (B & C) parameters. The combined analysis of optical absorption and EPR spectroscopy has indicated that the manganese ions exist in Mn2+ (in octahedral) local coordination sites. FTIR results showed that PO4 are the main structural unit of the glass system and the manganese ions are located in the glass matrix network.
International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
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.
Optimization of structure-property relationships in nickel ferrite.pdfProximaCentauri15
In this report, a detail analysis of the impact of annealing temperature on the structural, elastic, morphological,
optical, and magnetic behavior of NiFe2O4 nanoparticles prepared by the citrate sol-gel method is presented.
Analyzing the XRD patterns by the Rietveld method confirms that all the annealed samples have been crystallized
to cubic spinel structure belonging to Fd3 m space group with a single phase. Rietveld analysis demonstrates the
change in structural and microstructural parameters and movement of cations from tetrahedral to octahedral
sites and vice-versa upon annealing. The quantitative estimation of Ni2+ & Ni3+ and Fe2+ & Fe3+ has been carried
out using XPS analysis. Decreases in peak broadening and shift of five Raman active peaks towards higher frequency
upon annealing have been analyzed using the phonon confinement model. The variation in elastic parameters
with annealing temperature has been assessed by FTIR analysis. The UV analysis reveals the increase of
the optical energy band gap and the decrease of Urbach energy with annealing temperature enhancement. A
noticeable sharp absorption band at 748 nm in UV spectra is attributed to 3A2g(3F)→3T1g(3F) electronic transition.
Room temperature magnetic hysteresis loops exhibit an increase of saturation magnetization upon
annealing which is discussed with reference to finite size effects and disorderly surface spins. The estimated value
of magnetocrystalline anisotropy constant by Law of Approach to saturation (LAS) theory as well as coercivity
value elucidates the annealing effect in changing the magnetic single domain state of the particle to a multidomain
state. Analysis of ZFC and FC magnetization curve measured at 100 Oe in the temperature range 400
K–60 K reveals the significant impact of annealing temperature on magnetic anisotropy, inter-particle interaction,
and blocking temperature. Exploring the magnetic hysteresis loop measured in the temperature range
60–400 K over field strength of ± 3 T demonstrates the significant role of annealing on magnetic exchange
interaction. Temperature dependent behavior of saturation magnetization and coercivity has been analyzed
using modified Bloch’s law and Kneller’s relation. The magnetic heating efficiency examined by the induction
heating system reveals that the sample has enough potential for hyperthermia application.
Physical and Magnetic Properties of Manganese Ferrite NanoparticlesIJERA Editor
In this paper, manganese ferrite (MnFe2O4) nanoparticles were synthesized using chemical bath deposition (CBD) method and characterized by XRD and TEM to determine different properties of nanoparticles. The results obtained showed the formation of manganese ferrite nanoparticles with an average particle size are in good agreement with previous reported experimental results and displayed good magnetic properties. Magnetic properties was determined using Vibrating Sample Magnetometer(VSM). Due to simplicity and low cost of this process, it could be used for synthesis of ferrites nanoparticles. These materials may be used in drug delivery systems, electronic devices and water remediation.
Preparation and characterization of Al doped nano crystalline Ni ferritesIJERA Editor
The Ni-Al nano ferrites having compositional formula NiAlxFe2-xO4 (where x= 0.2, 0.4, 0.6, and 0.8) were synthesized by citrate gel auto combustion method. The XRD studies reflected that the fabricated powders were single phase spinel structure with crystallite sizes in the range of 17-26nm. The values of lattice parameter and X-ray density decreases with the decrease of composition. The observed results can be explained on the basis of composition
Microstructural and Magnetic Properties of Cobalt Ferrite Nanoparticles Synth...ijtsrd
Cobalt ferrite (CoFe2O4), an inverse spinal ferrite has high permeability, good saturation 1magnetization and no preferred direction of magnetization, high Curie temperature, and high electromagnetic performance. In the present work 0.2M cobalt nitrate 0.3M ferric nitrate and 0.4 M citric acid is used to synthesis cobalt ferrite nanoparticle by sol-gel technique. As the magnetic property depends on the grain size of the synthesized nanoparticle, metal nitrate to citric acid ratio is varied from 0.8, 0.6 and 0.4 and the structural, functional morphological and magnetic characteristics are analyzed. The structural analysis shows the decrease in the average crystallite from 37 to 27nm when CAMN ratio decreases from 0.8 to 0.4. The strain is directly proportional to dislocation density and it reflects the growth of the average grain size, and in the present study, it reflects the same. The calculated lattice parameter is found to be close to 8.373 Ã… and the volume of the cell is found to be 5.63x10-28 m is close to the standard value for the cobalt ferrite nanoparticles. From the EDS spectrum, the presence of Co, Fe, and O in the synthesized nanoparticles are noted. Functional groups analysis by FTIR shows the presence of organic sources. Surface morphology by Scanning electron microscope shows the distribution of spherical sized nanoparticles agglomerated in different sizes and the grain size calculated by image J software are close to the calculated value by Scherrer formula from XRD. Chitra | T Raguram | K S Rajni"Microstructural and Magnetic Properties of Cobalt Ferrite Nanoparticles Synthesized by Sol-Gel Technique" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-2 | Issue-5 , August 2018, URL: http://www.ijtsrd.com/papers/ijtsrd15871.pdf http://www.ijtsrd.com/physics/other/15871/microstructural-and-magnetic-properties-of-cobalt-ferrite-nanoparticles-synthesized-by-sol-gel-technique/chitra
Application of mixed colloidal magnetic fluid of single domain Fe3O4 and NiFe...IJERA Editor
Ferrofluids are stable suspensions of colloidal ferrimagnetic particles in suitable non – magnetic carrier liquids. They have attracted a lot of attention from scientists and engineers due to their many interesting properties and applications in various branches of engineering. The present work reports the performance of colloidal fluid of single domain nanoparticles of NiFe2O4 and Fe3O4. The thermal properties and its dynamics on magnetization as well as its effect on thermal conductivity on the colloidal fluid are studied here. Advantages of the increased thermal conductivity and optimization of magnetization of mixed colloidal fluid is used to extract the heat from voice coil. Nanoparticles of 21 nm of Fe3O4 and 12 nm of NiFe2O4 are used for mixed colloidal fluid. The suspension of particles is achieved by coating the nanoparticles with mono-corboxylic group on both the types of particles. The higher size (21 nm of Fe3O4 and 12 nm of NiFe2O4) particles are taken for synthesizing colloidal fluid, to have magnetic property of mixed colloidal liquid at elevated temperature of voice coil of speaker (Higher sized particles gives better magnetization). Oil is used as a carrier. Mixed magnetic colloidal fluid is used as a medium for damping so that noise is reduced at higher temperature of voice coil
A Simple Thermal Treatment Synthesis and Characterization of Ni-Zn Ferrite (N...IOSR Journals
Cubic structured nickel-zinc ferrite nanoparticles (Ni0.5Zn0.5Fe2O4) have been synthesized by thermal treatment method. This simple procedure employed an aqueous solution containing only metal nitrates as precursors, polyvinyl pyrrolidone as a capping agent, and deionized water as a solvent. The solution was thoroughly stirred for 2 hour, dried at 353 K for 3 hour, the dried material crushed into powder and calcined the powder at 873 K to remove organic substances and crystallize the particles. The microstructure properties of the prepared ferrite nanoparticles were measured using FTIR, XRD, TEM, and EDX and the magnetic properties were determined using VSM and EPR. The average particle size increased from 7 to 22 nm with the increase of calcination temperature from 723 to 873 K. The saturation magnetization, coercivity field, and g-factor increased respectively from 24 emu/g, 11 G, and 2.0673at 723 K to 38 emu/g, 60 G, and 2.1227 at 873 K. This method offers simplicity, a low cost, and an environmentally friendly operation since it produces no by-product effluents.
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).
Effect of Ytterbium Substitution on the Structural and Magnetic Properties of...ijtsrd
A series of ytterbium substituted Zinc ferrites Zn YbxFe1 x 2O4 with x=0.0000, 0.0125, 0.0250, 0.0375, 0.0500 was synthesized by the solid state method. The structural characterizations of all the prepared samples were done by using X ray diffraction XRD . These studies confirmed the formation of single phase structure in all compositions. The increase in the value of lattice parameter with increase in ytterbium concentration suggests the expansion of unit cell. Crystallinity and the crystallite size are observed to increase with the concentration of Ytterbium. The substitution of ytterbium strongly influences the magnetic characteristics and this is confirmed from the magnetization measurements at room temperature. Zar Zar Myint Aung "Effect of Ytterbium Substitution on the Structural and Magnetic Properties of Nanocrystalline Zinc Ferrite" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-5 , August 2019, URL: https://www.ijtsrd.com/papers/ijtsrd27826.pdf Paper URL: https://www.ijtsrd.com/physics/other/27826/effect-of-ytterbium-substitution-on-the-structural-and-magnetic-properties-of-nanocrystalline-zinc-ferrite/zar-zar-myint-aung
Pushing the limits of ePRTC: 100ns holdover for 100 daysAdtran
At WSTS 2024, Alon Stern explored the topic of parametric holdover and explained how recent research findings can be implemented in real-world PNT networks to achieve 100 nanoseconds of accuracy for up to 100 days.
Why You Should Replace Windows 11 with Nitrux Linux 3.5.0 for enhanced perfor...SOFTTECHHUB
The choice of an operating system plays a pivotal role in shaping our computing experience. For decades, Microsoft's Windows has dominated the market, offering a familiar and widely adopted platform for personal and professional use. However, as technological advancements continue to push the boundaries of innovation, alternative operating systems have emerged, challenging the status quo and offering users a fresh perspective on computing.
One such alternative that has garnered significant attention and acclaim is Nitrux Linux 3.5.0, a sleek, powerful, and user-friendly Linux distribution that promises to redefine the way we interact with our devices. With its focus on performance, security, and customization, Nitrux Linux presents a compelling case for those seeking to break free from the constraints of proprietary software and embrace the freedom and flexibility of open-source computing.
GraphSummit Singapore | The Future of Agility: Supercharging Digital Transfor...Neo4j
Leonard Jayamohan, Partner & Generative AI Lead, Deloitte
This keynote will reveal how Deloitte leverages Neo4j’s graph power for groundbreaking digital twin solutions, achieving a staggering 100x performance boost. Discover the essential role knowledge graphs play in successful generative AI implementations. Plus, get an exclusive look at an innovative Neo4j + Generative AI solution Deloitte is developing in-house.
In his public lecture, Christian Timmerer provides insights into the fascinating history of video streaming, starting from its humble beginnings before YouTube to the groundbreaking technologies that now dominate platforms like Netflix and ORF ON. Timmerer also presents provocative contributions of his own that have significantly influenced the industry. He concludes by looking at future challenges and invites the audience to join in a discussion.
PHP Frameworks: I want to break free (IPC Berlin 2024)Ralf Eggert
In this presentation, we examine the challenges and limitations of relying too heavily on PHP frameworks in web development. We discuss the history of PHP and its frameworks to understand how this dependence has evolved. The focus will be on providing concrete tips and strategies to reduce reliance on these frameworks, based on real-world examples and practical considerations. The goal is to equip developers with the skills and knowledge to create more flexible and future-proof web applications. We'll explore the importance of maintaining autonomy in a rapidly changing tech landscape and how to make informed decisions in PHP development.
This talk is aimed at encouraging a more independent approach to using PHP frameworks, moving towards a more flexible and future-proof approach to PHP development.
Dr. Sean Tan, Head of Data Science, Changi Airport Group
Discover how Changi Airport Group (CAG) leverages graph technologies and generative AI to revolutionize their search capabilities. This session delves into the unique search needs of CAG’s diverse passengers and customers, showcasing how graph data structures enhance the accuracy and relevance of AI-generated search results, mitigating the risk of “hallucinations” and improving the overall customer journey.
UiPath Test Automation using UiPath Test Suite series, part 4DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 4. In this session, we will cover Test Manager overview along with SAP heatmap.
The UiPath Test Manager overview with SAP heatmap webinar offers a concise yet comprehensive exploration of the role of a Test Manager within SAP environments, coupled with the utilization of heatmaps for effective testing strategies.
Participants will gain insights into the responsibilities, challenges, and best practices associated with test management in SAP projects. Additionally, the webinar delves into the significance of heatmaps as a visual aid for identifying testing priorities, areas of risk, and resource allocation within SAP landscapes. Through this session, attendees can expect to enhance their understanding of test management principles while learning practical approaches to optimize testing processes in SAP environments using heatmap visualization techniques
What will you get from this session?
1. Insights into SAP testing best practices
2. Heatmap utilization for testing
3. Optimization of testing processes
4. Demo
Topics covered:
Execution from the test manager
Orchestrator execution result
Defect reporting
SAP heatmap example with demo
Speaker:
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
Elevating Tactical DDD Patterns Through Object CalisthenicsDorra BARTAGUIZ
After immersing yourself in the blue book and its red counterpart, attending DDD-focused conferences, and applying tactical patterns, you're left with a crucial question: How do I ensure my design is effective? Tactical patterns within Domain-Driven Design (DDD) serve as guiding principles for creating clear and manageable domain models. However, achieving success with these patterns requires additional guidance. Interestingly, we've observed that a set of constraints initially designed for training purposes remarkably aligns with effective pattern implementation, offering a more ‘mechanical’ approach. Let's explore together how Object Calisthenics can elevate the design of your tactical DDD patterns, offering concrete help for those venturing into DDD for the first time!
Climate Impact of Software Testing at Nordic Testing DaysKari Kakkonen
My slides at Nordic Testing Days 6.6.2024
Climate impact / sustainability of software testing discussed on the talk. ICT and testing must carry their part of global responsibility to help with the climat warming. We can minimize the carbon footprint but we can also have a carbon handprint, a positive impact on the climate. Quality characteristics can be added with sustainability, and then measured continuously. Test environments can be used less, and in smaller scale and on demand. Test techniques can be used in optimizing or minimizing number of tests. Test automation can be used to speed up testing.
Securing your Kubernetes cluster_ a step-by-step guide to success !KatiaHIMEUR1
Today, after several years of existence, an extremely active community and an ultra-dynamic ecosystem, Kubernetes has established itself as the de facto standard in container orchestration. Thanks to a wide range of managed services, it has never been so easy to set up a ready-to-use Kubernetes cluster.
However, this ease of use means that the subject of security in Kubernetes is often left for later, or even neglected. This exposes companies to significant risks.
In this talk, I'll show you step-by-step how to secure your Kubernetes cluster for greater peace of mind and reliability.
A tale of scale & speed: How the US Navy is enabling software delivery from l...sonjaschweigert1
Rapid and secure feature delivery is a goal across every application team and every branch of the DoD. The Navy’s DevSecOps platform, Party Barge, has achieved:
- Reduction in onboarding time from 5 weeks to 1 day
- Improved developer experience and productivity through actionable findings and reduction of false positives
- Maintenance of superior security standards and inherent policy enforcement with Authorization to Operate (ATO)
Development teams can ship efficiently and ensure applications are cyber ready for Navy Authorizing Officials (AOs). In this webinar, Sigma Defense and Anchore will give attendees a look behind the scenes and demo secure pipeline automation and security artifacts that speed up application ATO and time to production.
We will cover:
- How to remove silos in DevSecOps
- How to build efficient development pipeline roles and component templates
- How to deliver security artifacts that matter for ATO’s (SBOMs, vulnerability reports, and policy evidence)
- How to streamline operations with automated policy checks on container images
Sudheer Mechineni, Head of Application Frameworks, Standard Chartered Bank
Discover how Standard Chartered Bank harnessed the power of Neo4j to transform complex data access challenges into a dynamic, scalable graph database solution. This keynote will cover their journey from initial adoption to deploying a fully automated, enterprise-grade causal cluster, highlighting key strategies for modelling organisational changes and ensuring robust disaster recovery. Learn how these innovations have not only enhanced Standard Chartered Bank’s data infrastructure but also positioned them as pioneers in the banking sector’s adoption of graph technology.
Removing Uninteresting Bytes in Software FuzzingAftab Hussain
Imagine a world where software fuzzing, the process of mutating bytes in test seeds to uncover hidden and erroneous program behaviors, becomes faster and more effective. A lot depends on the initial seeds, which can significantly dictate the trajectory of a fuzzing campaign, particularly in terms of how long it takes to uncover interesting behaviour in your code. We introduce DIAR, a technique designed to speedup fuzzing campaigns by pinpointing and eliminating those uninteresting bytes in the seeds. Picture this: instead of wasting valuable resources on meaningless mutations in large, bloated seeds, DIAR removes the unnecessary bytes, streamlining the entire process.
In this work, we equipped AFL, a popular fuzzer, with DIAR and examined two critical Linux libraries -- Libxml's xmllint, a tool for parsing xml documents, and Binutil's readelf, an essential debugging and security analysis command-line tool used to display detailed information about ELF (Executable and Linkable Format). Our preliminary results show that AFL+DIAR does not only discover new paths more quickly but also achieves higher coverage overall. This work thus showcases how starting with lean and optimized seeds can lead to faster, more comprehensive fuzzing campaigns -- and DIAR helps you find such seeds.
- These are slides of the talk given at IEEE International Conference on Software Testing Verification and Validation Workshop, ICSTW 2022.
SAP Sapphire 2024 - ASUG301 building better apps with SAP Fiori.pdfPeter Spielvogel
Building better applications for business users with SAP Fiori.
• What is SAP Fiori and why it matters to you
• How a better user experience drives measurable business benefits
• How to get started with SAP Fiori today
• How SAP Fiori elements accelerates application development
• How SAP Build Code includes SAP Fiori tools and other generative artificial intelligence capabilities
• How SAP Fiori paves the way for using AI in SAP apps
SAP Sapphire 2024 - ASUG301 building better apps with SAP Fiori.pdf
Io3614891497
1. K. Vijaya Kumar et al Int. Journal of Engineering Research and Applications
ISSN : 2248-9622, Vol. 3, Issue 6, Nov-Dec 2013, pp.1489-1497
RESEARCH ARTICLE
www.ijera.com
OPEN ACCESS
Structure-Property Correlation of Sol-Gel Processed
Co0.5Ti0.5ZnFeO4 Ceramic
K. Vijaya Kumar1*, M. Lakshmi2, M Buchi Suresh3
1
Department of Physics, Jawarharlal Nehru Technological University Hyderabad College of Engineering,
Nachupally (Kondagattu), Karimnagar-Dist., 505501, A. P, INDIA.
2
Department of Physics, SSJ Engineering College,V. N. Pally, Hyderabad, 500075, A.P., INDIA.
3
Centre for Ceramic Processing, International Advanced Research Centre for Powder Metallurgy and New
Materials, Balapur, Hyderabad, 500005, A. P., INDIA.
Abstract
Titanium doped Cobalt Zinc Ferrite nano powder of chemical composition Co0.5Ti0.5ZnFeO4 was synthesized
using sol-gel method and calcinated at different temperatures ranging from 500-800 0C. The X-ray diffraction
(XRD) and Fourier Transform Infrared techniques (FTIR), Scanning Electron Microscopy (SEM) and electrical
properties were carried out at room temperature. The grain size becomes larger with increase of calcination
temperature ranging from 47.71-83.62 nm. The X-ray diffraction studies reveal the formation of single phase
cubic spinel structure. The SEM micrographs show the uniform distribution of the particles, the average size
was estimated to be 0.350 μm. IR absorption bands are observed around 600 cm -1 and 400 cm-1 of the tetrahedral
and octahedral sites respectively. The effect of calcination temperature on electrical properties was studied and
conduction phenomenon in the samples is discussed.
Keywords: Ferrites, Sol-gel technique, XRD, SEM, EDS, FTIR, Dielectric constant, Dielectric loss
I. Introduction
In recent years, ferrite nano-particles have
drawn major attention because of their unique physical
properties, such as electrical conductivity, optical band
gap, refractive index and magnetic properties and
superior mechanical properties such as hardness of
nanomaterials and chemical properties compared with
their counterpart bulk materials. Polycrystalline nanoferrite particles have become immensely popular
magnetic materials for a wide variety of applications
such as electronic ignition systems, generators,
vending machines, medical implants, wrist watches,
inductor core, transformer circuits, magnetic sensors
and recording equipment, telecommunications,
magnetic fluids, microwave absorbers, other highfrequency applications, etc [1].
Cobalt–zinc ferrite as a special case has
interesting properties such as high mechanical
hardness, high Curie temperature, low porosity, high
chemical stability and reasonable cost [2]. They are
also used in radio-frequency circuits, high quality
filters, rod antennas, transformer cores, high-speed
digital tapes, read/write heads and other devices [3, 4].
A large number of methods have been developed to
prepare Co-Zn nano ferrite, such as
the coprecipitation, ceramic technique, forced hydrolysis,
microwave combustion method, salvo thermal method,
the standard solid- state reaction technique, solgel
method and the PEG – assisted hydro thermal method.
Among them we have selected the sol- gel method [5].
Sol-gel method has the advantage of good
stoichiometric control and production of ultrafine
www.ijera.com
particles with a uniform size distribution in a relatively
short processing time. It is a simple process, which
saves time and energy consumption over the
traditional methods and requires only low sintering
temperature [6]. Recent studies have shown that
reduction in the size of magnetic materials may lead to
novel properties improved better than to the properties
of the bulk materials, due to small volume (super
paramagnetism) or high surface to volume ratio (spin
canting).
The diversity in properties of ferrites has
paved the way for the development of a wide variety
of ferrites for various applications such as permanent
magnets and electrical and electronic compounds [7,
8]. Their properties are very sensitive to the type of
substitution and sintering conditions such as
temperature, time and heating rate [9]. A selective
magnetic dilution is very important in ferrites. The
nonmagnetic ions that can be used in such dilution
should have ionic radius comparable with that of the
magnetic ions. In this case we can improve the
electronic and magnetic properties of ferrite samples.
It is found that small substitution of Fe ions by rare
earth ion may favorably influence the magnetic and
electrical properties of ferrite. It is thus possible to
obtain a good magnetic material for use in high
frequency applications.
The interesting and useful magnetic and
electrical properties of soft ferrites are governed by the
choice of the cations along with Fe2+, Fe3+ ions and
their distribution between tetrahedral (A) and
octahedral (B) sites of the spinel ferrite, as well as
1489 | P a g e
2. K. Vijaya Kumar et al Int. Journal of Engineering Research and Applications
ISSN : 2248-9622, Vol. 3, Issue 6, Nov-Dec 2013, pp.1489-1497
preparation conditions [10]. Although a tremendous
work has been reported on Zn doped Cobalt ferrites,
but the simultaneously huge investigation is required
on the variation of electrical and magnetic properties
of Co-Zn nano ferrites with Ti4+ ions [11-13]. In the
present work, sol-gel method is used to prepare
Co0.5Ti0.5ZnFeO4 nano powder. Further the effect of
the annealing temperature on the structural, micro
structural and electrical properties of Co0.5Ti0.5ZnFeO4
was investigated. In the present work, systematic study
of the electrical impedance spectroscopy, X-ray
density, SEM, bulk density and porosity of cobalt zinc
ferrites have been carried out in order to find the
relationship of these properties with the annealing
temperature.
II. Experimental Procedure:
Fe(NO3)3.9H2O (99.0% pure LOBAL
Chemie), Zn(NO3)2 .6H2O (99.0% pure SDFCL),
Co(NO3)2 .6H2O (99.0% pure SDFCL), TiCl4 (99.0%
pure SDFCL) and C6H8O7.H2O (Hydrated citric
acid)(99.5% pure MERK) were used as raw materials.
Stoichiometric amount of metal nitrates and
appropriate dosage of citric acid are dissolved in
minimum quantity of deionised water and stirred well.
Citric acid helps the homogenous distribution of the
metal ions to get segregate from the solutions. After
adjusting the metal nitrate and citric acid ratio to 1:1,
the mixed solution was neutralized to a pH value of 7
by adding liquid ammonia, since the base catalysts are
employed in order to speed up the reaction. After the
mixed solution was heated at 60˚C on a hot plate and
continuously stirred using a magnetic stirrer for 1 hr,
the solution turned into brown sol. Then heated at
100˚C and stirred constantly, the sol became sticky
gel. Increasing the temperature up to 200˚C led to the
self-ignition of the gel. The dried gel burnt in a self –
propagating combustion reaction until all the gel was
completely burnt out to form a voluminous and fluffy
powder with a large surface area. This powder is
further crushed in agate mortar to obtain the nano
sized powder. The resultant powder is heated at
500oC, 600oC, 700oC and 800oC, respectively for 4 h
to form spinel CoZnTi Ferrite nano particles. The
maximum particle size after grinding was 83.62nm.
These powders were pressed into pellets. The diameter
and thickness of the pellets are 10 mm and 2 mm,
respectively. The pellets were calcinated for 4 h at
950oC.
The X-ray diffraction (XRD) patterns of all
the prepared samples were taken by X-ray
diffractometer using Cu Kα radiation (λ=1.54°A), The
diffraction peaks are broad because of the nano meter
size of the crystallite. A careful analysis of the XRD
patterns helps to determine the respective planes and
face centered cubic structure of these ferrites. Well
resolved peaks in XRD pattern clearly indicate the
single phase and polycrystalline nature of the samples.
The size of crystal is evaluated by measuring the full
width half maximum (FWHM) of the most intense
www.ijera.com
www.ijera.com
peak (311) from XRD and by using the Debye
Scherrer’s formula.
The size of the crystallite is evaluated using
the formula, 𝐷 =0.94λ / βCosθ, where D is the
crystallite size, λ is the wavelength of incident X-ray,
θ is the diffraction angle and β is the full-width at half
maximum (FWHM). For electrical characterization,
powders were compacted and sintered at 950 oC for 4
h. The AC impedance spectroscopy measurements
using two probe method were carried out with
solartron SI1260 impedance analyzer. For the
electrical measurements ohmic contacts were made by
using silver paste on two faces of the samples. For
temperature measurements specimens were placed in a
furnace where temperature could be controlled.
III. Results and discussion:The XRD patterns of Ti doped cobalt zinc
ferrite nano-particles at different calcinations
temperatures of 500, 600, 700 and 800 oC for 4 h are
shown in Fig. 1. Samples show the reflection planes of
(111), (220), (311), (222), (400), (422), (511) and
(440) which confirm the presence of single-phase of
ferrite phase with a face centered cubic structure.
Except for the impure phase of α-Fe2O3 which is found
in all calcined samples and occurs naturally as
hematite [14]. The XRD patterns also indicated
increase in crystallinity by increasing the calcination
temperature, due to the removal of stresses with the
heating process.
Table 1: Variation of particle size, crystallite size,
lattice constant and X-ray density with calcination
temperature.
SAMP Calcinati Crystal LATTIC X-RAY
LE
on
lite size
E
DENSI
Tempera
(D)
CONST
TY
ture
nm
ANT
g/cc
(˚C)
a(A˚)
R5
500
47.71
8.384
5.3702
R6
600
65.13
8.390
5.358
R7
700
83.38
8.392
5.354
R8
800
83.62
8.393
5.353
The values of particle size, lattice parameters
and X-ray density are furnished in Table-1. These
values are slightly lower than the lattice parameter of
the standard pattern (JCPDS 35-1373). From the table1, it can be clearly understood that with the increase of
the calcination temperature, the diffraction peaks
become sharper and increase in intensity. This
indicates intensification in crystallinity that originates
from the increment of crystalline volume ratio due to
particle size enlargement of the nuclei [15].
Fig. 2 shows the FTIR spectra of
Ti0.5Co0.5Zn1.0Fe1.0O4 nano particles of all the
considered samples in the range of 400 to 4000cm-1.
For ferrites, generally two assigned absorption bands
1490 | P a g e
3. K. Vijaya Kumar et al Int. Journal of Engineering Research and Applications
ISSN : 2248-9622, Vol. 3, Issue 6, Nov-Dec 2013, pp.1489-1497
appear around 600cm-1, which is attributed to
stretching vibration of tetrahedral group Fe-O and that
around 400cm-1, which is attributed to the octahedral
group complex Fe-O. The powders heat treated at
different temperatures show characteristic absorptions
of the ferrite phase with a strong absorption around
600cm-1 and another absorption in the range of 410450cm-1. The difference in the band positions with
calcination temperature is expected because of the
difference in the M2+-O2- distance for the octahedral
and tetrahedral groups. Waldron studied the
vibrational spectra of ferrites and attributed the sharp
absorption band around 600 cm-1 to the intrinsic
vibrations of the tetrahedral groups, and the other band
to that of the octahedral groups [16].
Fig. 3 shows the SEM images of
Co0.5Ti0.5ZnFeO4 ferrite prepared by sol-gel process
with different calcination temperatures. It can be seen
that the grain size becomes larger with the increase of
calcination temperature with the size range of 47.71 83.62 nm. The increase in grain size results in a
decrease of fraction of low coordinated atoms at the
surface skin of grains, which decreases the lattice
stresses due to inward shrinking atoms lying on the
surface. Therefore, the lattice parameter of the
prepared samples increased with an increase in grain
size. It is obvious that when cell volume increases, the
theoretical density decreases. Fig. 4 shows EDS
analysis of all the samples and it shows the presence of
elements such as Titanium, Cobalt, Zinc and Iron in all
the samples.
The particle size distributions of Ti doped
Co-Zn ferrite samples are shown in Fig. 5. The results
indicate that the samples prepared by the thermal
treatment method are uniform in morphology and
particle size distribution. The particle sizes increased
with increasing calcination temperature (Table 1). The
smallest particle size obtained in this study was 7 nm
for R5 and particle size reached to 47 nm at the
highest calcination temperature for R8. This suggests
that several neighboring particles fuse together to
increase particle sizes by melting their surfaces [17].
This grain growth of particle size enlargement at
higher calcination temperatures has been observed
previously in cobalt ferrite [18] and in zinc ferrite [19]
systems.
Fig. 6 shows the variation of the dielectric
constant with frequency measured at room
temperature. In all the samples the dielectric constant
decreases with increase in frequency exhibiting a
normal ferrimagnetic behaviour. A more dielectric
dispersion is observed at lower frequency region and it
remain almost independent of applied external field at
high frequency side. The sample R5 showed a
maximum dispersion while that R8 showed a least
frequency dependence. The dielectric dispersion
observed in the lower frequency region is due to
Maxwell–Wagner interfacial type of polarization,
which is in agreement with Koops phenomenological
theory [20]. The presence of Fe2+ ions in excess
www.ijera.com
www.ijera.com
amount favours the polarization effects. The decrease
in dielectric constant with increase in frequency is due
to lag of hopping frequency of electrons between Fe 2+
and Fe3+ ions against the frequency of external applied
ac field and becomes independent beyond a certain
limit. The plot of dielectric loss tangent (tanδ) against
log frequency is shown in Fig. 7. All the samples show
an increase in tanδ with frequency up to a certain
value and decreases with increasing frequency
indicating a maximum at about 100 kHz of applied
frequencies. Similar types of maxima in the plot of
loss tangent versus frequency have been reported for
doped Zn ferrite [21] and doped Ti ferrite [22] ferrite
systems. The R5 sample however, shows more
dielectric loss at low frequency region as compared to
other samples, which may be due to the presence of
space charge polarization resulting into the more
inhomogeneous dielectric structure [23]. The condition
for observing a maximum in the dielectric loss of a
material is given by the relation wτ=1, where
w=2Πfmax and τ is the relaxation time. Therefore, a
maximum can be observed when the jumping or
hopping frequency of electrons between Fe2+ and Fe3+
becomes nearly equal to the frequency of the applied
field [24]. The sharp peak can be observed when both
the frequencies exactly matches with each other.
To elicit more information about the
mechanism of electrical transport in this compound,
impedance measurements are carried out as a function
of frequency between 0.1 Hz and 10 MHz. The
impedance spectroscopy helps in the separation of
grain and grain boundary effects because each of them
has different relaxation times, resulting in separate
semi-circles in complex impedance plot. The
relaxation time (τ) is a parameter that depends on the
intrinsic properties of the material governing the
distribution of resistive and capacitive components in
the material. So, the results obtained using impedance
analyser are basically unambiguous and provide true
picture of the sample electrical behaviour.
Fig. 8 shows the variation of Z″ with
frequency at different temperatures. The plots show
that Z″ values attain a peak (Z″max) for all the
samples, which shifts to higher frequency with
increasing temperature and all the curves merge at
higher frequencies. The shifting of peaks towards
higher frequency indicates that the relaxation time is
decreasing with the increase of temperature. The peak
broadening with increasing temperature suggests the
presence of temperature dependent electrical
relaxation phenomenon in the material [25] and is due
to the material in-homogeneity of the polycrystalline
sample. The relaxation process is due to the presence
of space charges whose mobility increases at higher
temperature. This shift in frequency maxima indicates
active conduction through the grain boundary. The
magnitude of Z″max also decreases with increase in
temperature. The merger of Z″ values in the high
frequency domain may be possibly an indication of the
1491 | P a g e
4. K. Vijaya Kumar et al Int. Journal of Engineering Research and Applications
ISSN : 2248-9622, Vol. 3, Issue 6, Nov-Dec 2013, pp.1489-1497
accumulation of space charges in the material at low
frequency and at higher temperature.
Fig. 9 shows the plot of Z′ vs Z″ (Cole–Cole
plots) taken over a frequency range of 1 Hz–10MHz of
Ti doped cobalt zinc ferrite calcined at different
temperatures. It is observed that for R5-R7 samples
single deviated semicircular arc is observed and two
semicircular arcs could be traced for R8 sample with
different values of resistance for grain (Rg) and grain
boundary (Rgb). The high frequency semicircle
corresponds to a bulk contribution and low frequency
corresponds to grain boundary effect. Hence grain and
grain boundary effects could be separated at these
temperatures. The values of Rg and Rgb are obtained
from the intercepts of the traced semicircles with Z′
axis. It can be clearly noticed that the values of Rg and
Rgb decreases with rise in calcination temperature.
Two semicircle arcs of the impedance spectrum can be
expressed by an equivalent circuit consisting of a
parallel combination of low resistances and constant
phase elements connected in series. The spectrum
reveals relatively large grain boundary contribution to
the total resistivity because close to the grain
boundaries, transport properties of the materials are
controlled by imperfections, expected to be present in
higher concentration than in grains leading to an
additional contribution to the grain boundary
impedance. The internal space charge created at the
grain boundaries may lead to a significant increase in
the concentration of mobile effects. The peak
frequency for grain boundaries is much smaller than
that for grains due to their large resistance and
capacitance compared to those of grains.
The AC resistivity was calculated using the
formula ρ=Rx(t/A), where R is resistance. It is
observed that the AC resistivity decreases with
increase in calcinations temperature. Also the
resistivity of all the samples was found to decrease
with the increase in frequency upto 10MHz. The
conduction in ferrites is electronic in nature as
proposed by Verway [26]. The charge transfer takes
place owing to hopping of electrons between Fe2+ and
Fe3+ states at the octahedral sites of the spinel lattice.
A variation in electrical resistivity with temperature of
heat treatments in CoxFe3yxO4 system, has been
observed by Na et al. [27]. From the above results, it is
concluded that the decrease in electrical resistivity was
attributed to the increase in electron concentration.
IV. Conclusions
Co-Ti-Zn Ferrite with particle size of 7-47
nm were synthesized by sol-gel process and calcined
at different temperatures. Different particle size of
Co0.5Ti0.5ZnFeO4 ferrite powders were obtained by
varying the calcination temperature and the grain size
becomes larger with the increasing calcination
temperature. To stabilize the particles, they were
thermally treated at various temperatures from 623 to
823 K at which calcination occurred, thereby
stabilizing the particles, controlling the growth of the
www.ijera.com
www.ijera.com
nano-particles, preventing their agglomeration, and
creating a uniform distribution of particle sizes.
Particle sizes of 7–47 nm were obtained with
calcination temperatures between 623 and 823 K, as
confirmed by XRD and SEM analyses.
References
[1]
[2]
[3]
[4]
[5]
[6]
[7]
[8]
[9]
[10]
[11]
P M Prithviraj Swamy, S Basavaraja1,
Arunkumar Lagashetty2, N V Srinivas Rao3,
R Nijagunappa4 And A Venkataraman,
Synthesis and characterization of zinc ferrite
nanoparticles obtained by self- propagating
low- temperature combustion method, Bull.
Mater. Sci., Vol. 34, No.7, Dec.2011, pp.
1325-1330.
Vaidyanathan
G,
Sendhilnatha
S.,
Characterization
of
Co1-xZnxFe2O4
nanoparticles synthesized by co-precipitation
method, Physica B 2008; 403: 2157-2167
A.Hassadee, T.Jutarosaga, W.Onreabroy,
Effect of zinc substitution on structural and
magnetic properties of cobalt ferrite, Procedia
Engineering, 2012; 32: 597-602
Köseoglu Y, Baykal A, Gözuak F., Structural
and magnetic properties of CoxZn1-xFe2O4
nanocrystals synthesized by microwave
method, Polyhedron 2009; 28: 2887-2892.
Rani, Ritu, Sharma, S. K, Pirota, K. R,
Knobel, M, Thakur, Sangeeta, Singh. M,
Effect of Zinc concentration on the magnetic
properties of Cobalt-Zinc nanoferrite,
Ceramics International, 38 (2012) 2389-2394.
Dong Limin, Han Zhidong, Zhang Yaoming,
Wu Ze, Zhang Xianyou, Preparation and
sinterability of Mn-Zn Ferrite powders by
Sol-Gel method, J. Rareeaarths, Vol.24.
Dec.2006, p.54
A. Meenakshisundaram , N. Gunasekaran and
V.Srinivasan, Distribution of Metal Ions in
Transition Metal Manganites AMn2O4 (A:
Co, Ni, Cu, or Zn),Phys. Status. Solidi (a)
1982: 69 : k15.
B.V. Bhise, A.K. Ghatage, B.M. Kulkarni,
S.D. Lotke and S.A. Patil, Conduction in Mn
substituted Ni-Zn ferrites, Bull.Mater.Sci
1996;19 (3): 527.
M.M. El Sayed, Rare-earth substitution effect
on the quality of Mg-Ti ferrite, Ceramics
International 33 (2007) 413-418.
Gul, I.H., Maqsood, A., Structural, magnetic
and Electrical properties of Cobalt ferrites
prepared by sol-gel route., Journal of Alloys
and Compounds, 465 (2008) 227-231.
Sonal Singhal, Rimi Sharma, Tsering
Namgyal, Sheenu Jauhar, Santosh Bhukal,
Japinder Kaur, Structural, Electrical and
magnetic properties of Co0.5Zn0.5AlxFe2-x O4
(x=0, 0.2, 0.4, 0.6, 0.8 and 1.0) prepared via
sol-gel route., Ceramics International, 38
(2012) 2773-2778
1492 | P a g e
5. K. Vijaya Kumar et al Int. Journal of Engineering Research and Applications
ISSN : 2248-9622, Vol. 3, Issue 6, Nov-Dec 2013, pp.1489-1497
[12]
[13]
[14]
[15]
[16]
[17]
[18]
Ana Maria Rangel de Figueiredo Teixeiraa,
Tsuneharu Ogasawarab, Maria Cecília de
Souza Nóbregab, Investigation of Sintered
Cobalt-zinc
Ferrite
Synthesized
by
Coprecipitation at Different Temperatures: A
Relation between Microstructure and
Hysteresis Curves, Materials Research, Vol.
9, No. 3, 257-262, 2006
K.Muthuraman, Synthesis of Nano sized CeCo Doped Zinc Ferrite and their Permittivity
and Hysteresis Studies, International Journal
of Computer Applications (0975 – 8887)
Volume 32– No.3, October 2011
P. Laokul, V. Amornkitbamrung, S. Seraphin,
S. Maensiri, Characterization and magnetic
properties of nanocrystalline CuFe2O4,
NiFe2O4, ZnFe2O4 powders prepared by the
Aloe vera extract solution, Curr. Appl. Phys.
11 (2011) 101–108
Y.P. Sui, X.F. Huang, Z.Y. Ma, W. Li, F.
Qiao, K. Chen, K.J. Chen, The effect of
thermal annealing on crystallization in aSi:H/SiO2 multilayers by using layer by layer
plasma oxidation, J. Phys. Condens. Matter.
15 (2003) 5793–5800
R.D. Waldron, Phys. Rev. 99 (1955) 1727
K. Maaz, S. Karim, A. Mumtaz, S.K.
Hasanain, J. Liu, J.L. Duan, Synthesis and
magnetic characterization of nickel ferrite
nanoparticles prepared by coprecipitation
route, J. Magn. Magn. Mater. 321 (2009)
1838–1842
K. Maaz, A. Mumtaz, S.K. Hasanain, A.
Ceylan, Synthesis and magnetic properties of
6500
[19]
[20]
[21]
[22]
[23]
[24]
[25]
[26]
[27]
cobalt ferrite (CoFe2O4) nanoparticles
prepared by wet chemical route, J. Magn.
Magn. Mater. 308 (2007) 289–295
M.K. S Roy, B. Halder, H.C. Verma,
Characteristic length scales of nanosize zinc
ferrite, Nanotechnol. 17 (2006) 232–237
C.G. Koops, Phys. Rev., USA 83 (1951) 121
Batoo, Khalid Mujasam; Kumar, Shalendra;
Lee, Chan Gyu; Alimuddin, Study of
dielectric and ac impedance properties of Ti
doped Mn ferrites, Current Applied Physics
9(2009) 1397 – 1406.
M.B. Reddy, P.V. Reddy, Low-frequency
dielectric behaviour of mixed Li-Ti ferrites, J.
Phys. D: Appl. Phys. 24 (1991) 975
R.S. Patil, S.V. Kakatkar, P.K. Maskar, S.A.
Patil, S.R. Sawant, Dielectric behaviour of
Li0.5ZnxZrxFe2.5-2xO4 ferrites, Ind. J. Pure &
Appl. Phys. 29 (1991) 589
L.I. Rabinkin, L.I. Novikova, Ferrites
(Minsk) (1960) 146
J. R. Macdonald, Impedance Spectrosocpy
Emphasizing solid materials and systems,
John Wiley & Sons, New York, 1987, pp.
191-237
E.J. Verway, P.W. Hayman and F.C.
Romeign, Physical Properties and Cation
Arrangement of Oxides with Spinel
Structures II. Electronic Conductivity , J.
Chem. Phys., 15 (4) (1947)
J.G. Na, T.D. Lee and S.J. Park, IEEE Trans.
Magn., Effects of cation distribution on the
magnetic and electrical-properties of cobalt
ferrite,
28
(5)
(1992)
2433–2435
(311)
R5
R6
R7
R8
6000
5500
* (220) *
(222)
*
Intensity (arb. units)
5000
4500
4000
www.ijera.com
(422)
(220) (331)
(511)
* (440)
3500
3000
2500
2000
1500
1000
500
20
40
60
80
2
Fig.1: X-ray diffraction patterns of Co0.5Ti0.5ZnFeO4 powders calcinated at in the temperature range 500800 oC
www.ijera.com
1493 | P a g e
6. K. Vijaya Kumar et al Int. Journal of Engineering Research and Applications
ISSN : 2248-9622, Vol. 3, Issue 6, Nov-Dec 2013, pp.1489-1497
www.ijera.com
Fig.2: FTIR plots of Co0.5Ti0.5ZnFeO4 powders calcinated at in the
temperature range 500-700 oC
Fig.3: SEM images of Co0.5Ti0.5ZnFeO4 powders calcinated at in the
temperature range 500-800 oC
www.ijera.com
1494 | P a g e
7. K. Vijaya Kumar et al Int. Journal of Engineering Research and Applications
ISSN : 2248-9622, Vol. 3, Issue 6, Nov-Dec 2013, pp.1489-1497
www.ijera.com
Fig.4: EDS analysis of Co0.5Ti0.5ZnFeO4 powders calcinated at in the temperature range 500, 600, 700 &
800 oC (top to bottom)
Fig.5: Particle size distribution of the powders heat treated at different temperatures
www.ijera.com
1495 | P a g e
8. K. Vijaya Kumar et al Int. Journal of Engineering Research and Applications
ISSN : 2248-9622, Vol. 3, Issue 6, Nov-Dec 2013, pp.1489-1497
www.ijera.com
Fig.6: Variation of capacitance with frequency
Fig.7: Variation of dielectric loss tangent with frequency
www.ijera.com
1496 | P a g e
9. K. Vijaya Kumar et al Int. Journal of Engineering Research and Applications
ISSN : 2248-9622, Vol. 3, Issue 6, Nov-Dec 2013, pp.1489-1497
www.ijera.com
Fig.8: Variation of Z″ with frequency at different temperatures of Co0.5Ti0.5ZnFeO4
Fig.9: Cole-Cole plots in the frequency range 1 Hz-10 MHz of Co0.5Ti0.5ZnFeO4
www.ijera.com
1497 | P a g e