This document summarizes a study on the microstructure and dielectric properties of manganese (Mn) substituted strontium copper hexaferrite (Sr2Cu2Fe12O22) powder. Hexagonal ferrites have a complex crystalline structure built from spinel blocks. The study synthesized Sr2Cu2-xMnxFe12O22 powders with x = 0.0, 0.6, 0.8, 1.0 using a co-precipitation method. Characterization using XRD, FTIR and SEM confirmed the formation of a single Y-type hexaferrite phase. Dielectric measurements from 102 Hz to 2x106 Hz showed Mn substitution did not affect the phase but increased
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.
Synthesis of flower-like magnetite nanoassembly: Application in the efficient...Pawan Kumar
A facile approach for the synthesis of magnetite microspheres with flower-like morphology is reported
that proceeds via the reduction of iron(III) oxide under a hydrogen atmosphere. The ensuing magnetic
catalyst is well characterized by XRD, FE-SEM, TEM, N2 adsorption-desorption isotherm, and
Mössbauer spectroscopy and explored for a simple yet efficient transfer hydrogenation reduction of a
variety of nitroarenes to respective anilines in good to excellent yields (up to 98%) employing hydrazine
hydrate. The catalyst could be easily separated at the end of a reaction using an external magnet and
can be recycled up to 10 times without any loss in catalytic activity.
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.
Synthesis of flower-like magnetite nanoassembly: Application in the efficient...Pawan Kumar
A facile approach for the synthesis of magnetite microspheres with flower-like morphology is reported
that proceeds via the reduction of iron(III) oxide under a hydrogen atmosphere. The ensuing magnetic
catalyst is well characterized by XRD, FE-SEM, TEM, N2 adsorption-desorption isotherm, and
Mössbauer spectroscopy and explored for a simple yet efficient transfer hydrogenation reduction of a
variety of nitroarenes to respective anilines in good to excellent yields (up to 98%) employing hydrazine
hydrate. The catalyst could be easily separated at the end of a reaction using an external magnet and
can be recycled up to 10 times without any loss in catalytic activity.
Electrochemical Synthesis of MoO3 Nanoparticles Effect of Temperature Convert...IJERA Editor
MoO3 nanorods were prepared by electrochemical reduction method using the tetra propyl ammonium bromide (TPAB) was structure directing agent in an organic medium viz. tetra hydro furan (THF) and acetonitrile (ACN) in 4:1 ratio and at current density 14mA &18 mA. The reduction process takes place under atmospheric condition over a period of 2 h. Dried sample was calcinated in muffle furnace at 500ºC. The parameters such as current density and concentration of stabilizers were used to control the size of nanorods. The synthesized MoO3 nanorods were characterized by using UV-Visible, FT-IR, XRD, SEM-EDS and TEM analysis techniques.
Removal of lead ions by nife2 o4 nanoparticleseSAT Journals
Abstract Nickel ferrite nanoparticles have been prepared by polymeric precursor method. The nanoparticles application in the removal of lead ion was investigated. The results showed that the adsorptive properties were dependent on pH, duration and temperature. Highest percentage (99%) lead adsorption was observed under basic condition at room temperature during 1 h stirring. Analysis of lead adsorbed nickel ferrite by powder XRD, FTIR and XPS techniques revealed the adsorption took place based on hydroxide mechanism. The lead salt formed on the surface of the ferrite powder was identified to be lead carbonate and lead hydroxy carbonate at pH 7 and 9 respectively. Keywords: Nickel ferrite; Nanoparticles; Lead; Adsorption; Hydroxide
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.
Maiyalagan,Electro oxidation of methanol on ti o2 nanotube supported platinum...kutty79
TiO2 nanotubes have been synthesized using anodic alumina membrane as template. Highly dispersed
platinum nanoparticles have been supported on the TiO2 nanotube. The supported system
has been characterized by electron microscopy and electrochemical analysis. SEM image shows
that the nanotubes are well aligned and the TEM image shows that the Pt particles are uniformly
distributed over the TiO2 nanotube support. A homogeneous structure in the composite nanomaterials
is indicated by XRD analysis. The electrocatalytic activity ofthe platinum catalyst supported on
TiO2 nanotubes for methanol oxidation is found to be better than that of the standard commercial
E-TEK catalyst.
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.
Mapping of chemical order in inorganic compoundsJoke Hadermann
Presentations of some of the possibilities of observing cation and anion order in perosvkite based structures in order to solve their structure or to solve other questions, when they could not be solved by bulk diffraction techniques. The examples include a (Pb,Bi)FeO3-d compound, a solid oxide fuel cell compound Sr(Nb,Co,Fe)O3-d and several brownmillerite related compounds, as well as a "relaxor ferromagnetic". This was an invited lecture given at the Spring meeting of the British Crystallographic Association in 2014.
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.
Low Temperature Synthesis of Ba3Ta2ZnO9 (BZT) and Ba3Nb2ZnO9 (BZN) by Wet Che...IJASCSE
Powders of high microwave dielectric material Barium Zinc Tantalate (BZT) and Barium Zinc Niobate (BZN) have been prepared by wet chemical procedure at moderately low temperature ~5000C. Co-precipitate and mechanical mixtures of hydroxide of Ba(II), Ta(V)/Nb(V) & Zn(II) in 3:2:1 mole proportion on thermal decomposition, showed formation of the desired perovskite phase at 5000C. The product of co-precipitate and mechanical mixture of hydroxides heated upto7400C produced single phase BZT. Thermal decomposition of mixture was studied in static air atmosphere by TG & DTA. XRD studies on a sample heated to 500, 740, 780 & 9000C confirmed the formation of single phase BZT formation at 7400C and that of BZN at7800C.
Formation and Characterization of Mixed Crystals Based on Bis (Thiourea)Cadmi...IJERA Editor
Bis(thiourea)cadmium chloride(BTCC) and bis(thiourea)cadmium iodide (BTCI) are metal complexes of thiourea having better nonlinear optical properties than KH2PO4. An attempt has been made in the present study to form mixed crystals based on BTCC and BTCI (even though their crystal lattices mismatch) from aqueous solutions, the precursors mixed in proper proportions. A total of seven (including the end members) crystals were formed by the free evaporation method and characterized chemically, structurally, thermally, optically and electrically. The X-ray diffraction measurements indicate that (BTCC)X(BTCI)1-X crystals with x=1.0,0.8 and 0.6 are orthorhombic in structure with space group Pmn21 and that with x=0.5, 0.4, 0.2 and 0.0 are monoclinic in structure with space group P21/c. All the grown crystals are found to be thermally stable up to 215 °C and possessing wide optical transmission window (300-900 nm) which is suitable for NLO applications. The electrical measurements indicate that the grown crystals exhibit a normal dielectric behavior. The results obtained in the present study indicate that mixed crystals can be formed from the isomorphous precursors directly even though the end member’s crystals have lattice mismatching.
Electrochemical Synthesis of MoO3 Nanoparticles Effect of Temperature Convert...IJERA Editor
MoO3 nanorods were prepared by electrochemical reduction method using the tetra propyl ammonium bromide (TPAB) was structure directing agent in an organic medium viz. tetra hydro furan (THF) and acetonitrile (ACN) in 4:1 ratio and at current density 14mA &18 mA. The reduction process takes place under atmospheric condition over a period of 2 h. Dried sample was calcinated in muffle furnace at 500ºC. The parameters such as current density and concentration of stabilizers were used to control the size of nanorods. The synthesized MoO3 nanorods were characterized by using UV-Visible, FT-IR, XRD, SEM-EDS and TEM analysis techniques.
Removal of lead ions by nife2 o4 nanoparticleseSAT Journals
Abstract Nickel ferrite nanoparticles have been prepared by polymeric precursor method. The nanoparticles application in the removal of lead ion was investigated. The results showed that the adsorptive properties were dependent on pH, duration and temperature. Highest percentage (99%) lead adsorption was observed under basic condition at room temperature during 1 h stirring. Analysis of lead adsorbed nickel ferrite by powder XRD, FTIR and XPS techniques revealed the adsorption took place based on hydroxide mechanism. The lead salt formed on the surface of the ferrite powder was identified to be lead carbonate and lead hydroxy carbonate at pH 7 and 9 respectively. Keywords: Nickel ferrite; Nanoparticles; Lead; Adsorption; Hydroxide
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.
Maiyalagan,Electro oxidation of methanol on ti o2 nanotube supported platinum...kutty79
TiO2 nanotubes have been synthesized using anodic alumina membrane as template. Highly dispersed
platinum nanoparticles have been supported on the TiO2 nanotube. The supported system
has been characterized by electron microscopy and electrochemical analysis. SEM image shows
that the nanotubes are well aligned and the TEM image shows that the Pt particles are uniformly
distributed over the TiO2 nanotube support. A homogeneous structure in the composite nanomaterials
is indicated by XRD analysis. The electrocatalytic activity ofthe platinum catalyst supported on
TiO2 nanotubes for methanol oxidation is found to be better than that of the standard commercial
E-TEK catalyst.
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.
Mapping of chemical order in inorganic compoundsJoke Hadermann
Presentations of some of the possibilities of observing cation and anion order in perosvkite based structures in order to solve their structure or to solve other questions, when they could not be solved by bulk diffraction techniques. The examples include a (Pb,Bi)FeO3-d compound, a solid oxide fuel cell compound Sr(Nb,Co,Fe)O3-d and several brownmillerite related compounds, as well as a "relaxor ferromagnetic". This was an invited lecture given at the Spring meeting of the British Crystallographic Association in 2014.
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.
Low Temperature Synthesis of Ba3Ta2ZnO9 (BZT) and Ba3Nb2ZnO9 (BZN) by Wet Che...IJASCSE
Powders of high microwave dielectric material Barium Zinc Tantalate (BZT) and Barium Zinc Niobate (BZN) have been prepared by wet chemical procedure at moderately low temperature ~5000C. Co-precipitate and mechanical mixtures of hydroxide of Ba(II), Ta(V)/Nb(V) & Zn(II) in 3:2:1 mole proportion on thermal decomposition, showed formation of the desired perovskite phase at 5000C. The product of co-precipitate and mechanical mixture of hydroxides heated upto7400C produced single phase BZT. Thermal decomposition of mixture was studied in static air atmosphere by TG & DTA. XRD studies on a sample heated to 500, 740, 780 & 9000C confirmed the formation of single phase BZT formation at 7400C and that of BZN at7800C.
Formation and Characterization of Mixed Crystals Based on Bis (Thiourea)Cadmi...IJERA Editor
Bis(thiourea)cadmium chloride(BTCC) and bis(thiourea)cadmium iodide (BTCI) are metal complexes of thiourea having better nonlinear optical properties than KH2PO4. An attempt has been made in the present study to form mixed crystals based on BTCC and BTCI (even though their crystal lattices mismatch) from aqueous solutions, the precursors mixed in proper proportions. A total of seven (including the end members) crystals were formed by the free evaporation method and characterized chemically, structurally, thermally, optically and electrically. The X-ray diffraction measurements indicate that (BTCC)X(BTCI)1-X crystals with x=1.0,0.8 and 0.6 are orthorhombic in structure with space group Pmn21 and that with x=0.5, 0.4, 0.2 and 0.0 are monoclinic in structure with space group P21/c. All the grown crystals are found to be thermally stable up to 215 °C and possessing wide optical transmission window (300-900 nm) which is suitable for NLO applications. The electrical measurements indicate that the grown crystals exhibit a normal dielectric behavior. The results obtained in the present study indicate that mixed crystals can be formed from the isomorphous precursors directly even though the end member’s crystals have lattice mismatching.
IMPROVEMENT IN MORPHOLOGICAL AND ELECTRO-MAGNETIC BEHAVIOUR OF HARD FERRITE P...Editor IJMTER
The Ni-Ir substituted strontium ferrite of Sr(Ni-Ir)xFe12-2xO19 (x = 0.02 & 0.08) were
synthesized by sol-gel auto combustion technique and characterized using X-ray diffraction (XRD),
Transmission Electron Microscopy (TEM) for morphological behaviour with electrical
characteristics using Impedance Analyzer. XRD results confirmed the formation of a single phase
M-type hexagonal unit cell of space group P63/mmc. The increase in Ni-Ir concentration increases
the lattice parameter. TEM analysis of the sample demonstrates the formation of nano-size particles
which decreases with substitution. In this paper we reported the variation of dielectric constant,
dielectric loss, tangent loss, conductivity and magnetic behaviour with composition with temperature
and frequency analysis of the sample. The migration of Fe3+ ion from octahedral to tetrahedral site
decreases the dielectric constant with increase in Ni-Ir concentration. Activation energies were
found similar with calculated at ferromagnetic and paramagnetic region. The material study we
confined that the activation energy in the paramagnetic region is higher than that in the
ferromagnetic region. The enhanced resistivity of Ni-Ir substituted strontium hexaferrites is a
prospective application in high frequency and in microwave devices development.
Cation distribution of Ni2+ and Mg2+ ions improve structure and Magnetic Prop...AI Publications
In the present work, ferromagnetic Ni is slightly substituted for diamagnetic Mg spinal ferrites. The effect of Ni doping on the structural and magnetic properties of ferrites material in the form of NixMg1-xFe2O4 (x = 0.1,0.15,0.2,0.25, .0.3,0.35) has been the study. The Sol-gel auto Combustion method used to combine these substances uses urea as fuel. Sintered samples were shown using X-ray diffraction, Fourier Transform Infrared spectroscopy (FTIR) and a vibrating magnetometer sample. X-ray diffraction revealed that all the composite samples were pure cubic spinel arrays with a Fd3m space band and a permanent lattice that varied with Ni concentrations. the distribution of Ni2 + ions and Mg2+ ions in spinel ferrites indicates various changes in parameters such as tetrahedral ionic radius (rA), octahedral ionic radius (rB), hopping length (LA and LB). Fourier Transform Infrared (FT-IR) simulations showed wire vibration at the tetrahedral site and Octahedral site. spinel ferrites M-H curves are recorded at room temperature indicating normal hysteresis loop indicating the magnetic field.
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)
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
Microstructural and Dielectric Characterization of Sr doped Ba(Fe0.5Ta0.5)O3 ...theijes
Solid state reaction method was used to synthesize Ba1-xSrx(Fe0.5Ta0.5)O3 ceramic(x=0, 0.1, 0.2, 0.3, 0.4 and 0.5). The raw materials of making Sr doped Ba(Fe0.5Ta0.5)O3 were BaCO3, SrCO3, Fe2O3, Ta2O5 (purity better than 99%). Pellet and ring shaped samples prepared from each composition were sintered at 1400 and 1450ºC for 5 hour. The phase formation of Ba1-xSrx(Fe0.5Ta0.5)O3 was checked using X-ray diffraction (XRD) technique and observed a cubic perovskite crystal structure in space group Pm3m (221). Microstructure of the individual compound was examined by the field emission scanning electron micrograph (FESEM). Grain size was found to be varied with Sr content. The lattice parameter decreased with increasing Sr content. Dielectric spectroscopy was applied to investigate the electrical properties of BSFT at room temperature and in a frequency range of 100Hz–100 MHz. An analysis of the dielectric constant εʹ and loss tangent tan with frequency was performed assuming a distribution of relaxation times. The low frequency dielectric dispersion corresponds to the DC electrical conductivity.
Modulus spectroscopy study on Ferroelectric Lithium and Titanium modified Lea...iosrjce
IOSR Journal of Applied Physics (IOSR-JAP) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of physics and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in applied physics. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Dielectric behaviour of Ni+2 substituted Cu Co Nanocrystalline Spinel Ferrite...inventionjournals
Herein, the dielectric properties such as permittivity (real part ε’ and imaginary part ε”) and dielectric loss tangent (tan δ) are reported for the series [Nix Cu(constant) Co0.8-x Fe2O4] where constant=0.2 with x=0.2, 0.4 and 0.6 of ferrites, prepared by Sol-Gel auto-combustion technique by using high purity metal nitrate and citric acid as a catalyst. The variation in the real part (ε’) of dielectric constant , imaginary part ( ε”) of dielectric constant and dielectric loss tangent (tan δ) are studied at room temperature in the frequency range of 100 Hz to 5 MHz. Structural characterization of the annealed samples was done with the help of X-ray diffraction method. The particle size and single phase formation of NiCuCoFe2O4 ferrite was confirmed by Xray diffraction analysis and TEM. The particle size of prepared sample was confirmed by Scherer’s formula. The effect on Particle size (t) and lattice constant (Å) is observed due to substitution of Ni2+ in Cu Co. The digital LCR meter is used to obtain the magnetic properties of prepared pallets. The variations in the structural and dielectric properties of the prepared ferrite material are discussed.
Dielectric behaviour of Ni+2 substituted Cu Co Nanocrystalline Spinel Ferrite...inventionjournals
Herein, the dielectric properties such as permittivity (real part ε’ and imaginary part ε”) and dielectric loss tangent (tan δ) are reported for the series [Nix Cu(constant) Co0.8-x Fe2O4] where constant=0.2 with x=0.2, 0.4 and 0.6 of ferrites, prepared by Sol-Gel auto-combustion technique by using high purity metal nitrate and citric acid as a catalyst. The variation in the real part (ε’) of dielectric constant , imaginary part ( ε”) of dielectric constant and dielectric loss tangent (tan δ) are studied at room temperature in the frequency range of 100 Hz to 5 MHz. Structural characterization of the annealed samples was done with the help of X-ray diffraction method. The particle size and single phase formation of NiCuCoFe2O4 ferrite was confirmed by Xray diffraction analysis and TEM. The particle size of prepared sample was confirmed by Scherer’s formula. The effect on Particle size (t) and lattice constant (Å) is observed due to substitution of Ni2+ in Cu Co. The digital LCR meter is used to obtain the magnetic properties of prepared pallets. The variations in the structural and dielectric properties of the prepared ferrite material are discussed
Synthesis of flower-like magnetite nanoassembly: Application in the efficient...Pawan Kumar
A facile approach for the synthesis of magnetite microspheres with flower-like morphology is reported
that proceeds via the reduction of iron(III) oxide under a hydrogen atmosphere. The ensuing magnetic
catalyst is well characterized by XRD, FE-SEM, TEM, N2 adsorption-desorption isotherm, and
Mössbauer spectroscopy and explored for a simple yet efficient transfer hydrogenation reduction of a
variety of nitroarenes to respective anilines in good to excellent yields (up to 98%) employing hydrazine
hydrate. The catalyst could be easily separated at the end of a reaction using an external magnet and
can be recycled up to 10 times without any loss in catalytic activity.
Synthesis of flower-like magnetite nanoassembly: Application in the efficient...
Bw24494498
1. Rajshree B. Jotania, Pratiksha A. Patel / International Journal of Engineering Research and
Applications (IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue 4, July-August 2012, pp.494-498
Microstructure and Dielectric Properties of Mn Substituted
Sr2Cu2Fe12O22 (Cu2Y) Hexaferrite Powder
Rajshree B. Jotania*, Pratiksha A. Patel**
*(Department of Physics, University School of sciences, Gujarat University, Navrangpura, Ahmedabad 380 009,
Gujarat, India)
** (Samarth College of Engineering & Technology, Himmatnagar 383 001, Gujarat, India)
ABSTRACT
Hexaferrites are relatively low cost, composition Fe6O8 which is also known as spinel
chemically stable material and they have found block.
wide range of technological applications in The Y-structure can be built up from spinel blocks of
transformer core, high-quality filters, electronic, two oxygen layers which are connected by a block T,
microwave devices and components. Among all one above the other, two layers with barium ions. The
hexaferrites, Y-type hexaferrite is an important layers containing barium (or strontium or lead) are
type of magnetic materials in VHF and UHF and hexagonal packed with respect to their adjacent
has gained much interest in recent years due to oxygen layer. These barium ions are larger than the
their multiferroic properties. In this paper we oxygen ions. Therefore the distance between the
report the microstructural and dielectric oxygen layers which contain no barium ion. The
properties of the polycrystalline bulk samples of distances are 2.40 and 2.32Å respectively. The
Sr2Cu2-xMnxFe12O22 (x = 0.0, 0.6, 0.8, 1.0) projection of the distance between the centers of the
hexaferrite prepared by using a chemical co- Ba ions on to the axis is 2.90Å, from which it
precipitation synthesis. All hexaferrite samples follows that the centers of the barium ions lies at a
were characterized using XRD, FTIR, SEM and distance of 0.25Å out of the plane of the nearest
dielectric measurements. X-ray results confirm oxygen layer [1, 2]. The unit cell with hexagonal
that Mn substitution for Cu does not affect the symmetry (space group R m) consists of 18 oxygen
Y-type hexaferrite phase formation. Dielectric
layers with a repeat distance extending through only
measurements were carried out at room
six oxygen layers.the length of the c axis being
temperature in frequency range of 102 Hz to
43.56Å. In the hexagonal element cell each layer
2x106Hz.
again contain four large ions. There are four
Keywords - Y-type hexaferrite, co-precipitation successive layers of four oxygen ions, followed by
technique, XRD, SEM, Dielectric properties two layers each containing three oxygen ions and
one barium ion. The unit cell is composed of the
I. INTRODUCTION sequence STSTST including three formula units. The
Hexagonal ferrites are classified on the basis of metallic cations are distributed among six sublattices
their chemical composition and crystal structure. as shown in table 1. Three octahedral ions of
They are subdivided into six types: M-type sublattices 6cVI and 3bVI lies on a vertical threefold
(AFe12O19), W-type (AMe2Fe16O27), X-type axis while the central 3bVI, ion sharing two faces of
(A2Me2Fe28O46), Y-type (A2Me2Fe12O22), Z-type its coordination with the adjacent 6cVI ions inside T
(A3Me2Fe24O41) and U-type (A4Me2Fe36O60); where block. Such a configuration possesses a higher
A represents ions like Ba, Sr or Pb, and Me potential energy of the structure due to a stronger
represents divalent metal ions like Mg or Zn. The electrostatic repulsion between the cations; therefore
crystalline and magnetic structures of the different such sites are likely to be preferred by low charge
types of hexaferrites are remarkably complex and can ions. The Y-type hexagonal hexaferrites have gained
be considered as a superposition of T, R and S blocks much interest in recent years due to their multiferroic
along the hexagonal c-axis. Where T block of four properties [3-5]. These ferrites are used in electronic
types of oxygen ions (O4-BaO3-BaO3-O4) with the communication, microwave devices and
composition Ba2Fe8O14, R is a three oxygen layer components6. Miniaturization of ferrite devices in the
block (O4-BaO3-O4) with the composition BaFe6O11, electronic communication requires high-permeability
S block is a two oxygen layer block (O4-O4) with materials at relatively lower microwave frequencies
(0–10 GHz) and Y-type hexaferrite considered as
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2. Rajshree B. Jotania, Pratiksha A. Patel / International Journal of Engineering Research and
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Vol. 2, Issue 4, July-August 2012, pp.494-498
potential material for technical applications. High and was kept at room temperature 24 hours for aging.
permeability in Y-type ferrite is attributed to spin The obtained precipitates were washed in 1:1 mixture
rotation and domain wall motions. Y-type hexaferrite of methanol and acetone followed by 100% de
is an important type of soft magnetic materials in ionized water to remove impurities. The precipitate
VHF and UHF [7-14]. was dried at 80°C for 24 hours in an oven and then
calcined at 950°C for 4 hours followed by furnace
Table 1. Number of ions per unit formula, cooling to room temperature to get final product of
coordination and spin orientation for the various Sr2Cu2-XMnXFe12O22 hexaferrite powder.
metallic sublattices of Y-structure [15].
2.2 Characterization
Sublattice Coordination Block Number The Fourier transformed infrared spectra
of ions Spin (FTIR) of dried precursors and calcinated powder
were recorded at room temperature by the KBr pellet
6cIV tetrahedral S 2 Down method using a FTIR Brucker tensor 27 model. Phase
and quantitative analysis were performed by X-ray
3aVI octahedral S 1 UP diffraction using CuKα radiation (λ = 1.5405Å) on
PW1830 diffractometer. The 2θ Bragg angles were
8hVI octahedral S-T 6 UP scanned over a range of 18-90°. Scanning electron
micrographs were obtained using a MAKE-
6cVI octahedral T 2 Down
LEO/LICA Model STEROECAN 440 scanning
6cIV tetrahedral T 2 Down electron microscope. The dielectric properties of
Sr2Cu2-XMnXFe12O22 (x= 0.0, 0.6, 0.8 and 1.0)
3bVI octahedral T 1 UP samples were investigated using an Agilent
Precision LCR meter (Model No. E4980A).
The physical properties of Y-type hexaferrite
depends on many factors like preparation methods, III RESULTS AND DISCUSSION
sintering temperature, time, chemical composition
and amount of substitution etc. Many studies have 3.1 FTIR analysis
been reported on addition of divalent, trivalent and
tetravalent ions in Y-hexaferrites [16-21], but FTIR spectra of dried precursors and
according to our knowledge none has reported Mn calcinated samples was taken for x = 0.8 and 1.0
substituted Y-type strontium-copper hexaferrite. Our samples in order to monitor the structural changes
work focuses on the Physical and dielectric studies of during the synthesis process.
Mn doped Y-type hexaferrite prepared. For this
purpose Y-type hexaferrite with composition
Sr2Cu2-XMnXFe12O22 (x = 0.0, 0.6, 0.8 and 1.0) has
been prepared using a co-precipitation technique.
II. EXPERIMENTAL PROCEDURE
2.1 Powder preparation
Single-phase hexaferrite powders of Mn
doped Cu2Y with composition Sr2Cu2-xMnxFe12O22
(x = 0.0, 0.6, 0.8, 1.0) were produced by using a co-
precipitation technique. A. R. Grade powder of
strontium nitrate (Sr(NO3)2·6H2O), ferric nitrate
(Fe(NO3)2·9H2O), copper sulfate (CuSO4),
Manganese nitrate (Mn(NO3)2·4H2O) were used as
starting materials. Stoicheometric amount of
strontium nitrate, ferric nitrate, copper sulfate and
manganese nitrate were mixed in an appropriate
amount of de-ionized water. Ammonium solution Fig. 1(a) FTIR Spectra of Sr2Cu2-xMnxFe12O22
(30% w/v) was added slowly in the mixture to adjust (x=0.8) hexaferrite sample
pH of 8. The mixed solution was stirred for two hours
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3. Rajshree B. Jotania, Pratiksha A. Patel / International Journal of Engineering Research and
Applications (IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue 4, July-August 2012, pp.494-498
Where h, k, l are miller indices and d is inter planer
distance. type
The unit cell volume V of hexagonal crystal is
obtained from equation (2)
Unit cell volume, (2)
The value of lattice constants and cell volume of
prepared hexaferrite samples are listed in table 1.
From the XRD results, it is evident that mono phase
of Strontium Magenise hexaferrite produces at
temperature of 950ºC.
Fig. 1(b) FTIR Spectra of Sr2Cu2-xMnxFe12O2
[3017]
[116]
[0013]
(x=1.0) hexaferrite sample
[1128]
Figure 1 shows the FTIR spectra of as
[3019]
[305]
[215]
prepared precipitates and the calcinated samples in
[0210]
[0029]
[110]
the wave number range from 4000 cm-1 to 400 cm-1.
[0018]
[2132]
Figure 1 (a, b) shows FTIR spectra of dried
[1130]
Intensity (arb. unit)
[1121]
[119]
[3025]
precursors (heated at 40°C for 24 hrs) and Sr2Cu2- X= 0.0
[024]
XMnXFe12O22 (x = 0.8 and 1.0) hexaferrite particles
calcinated at 950°C, respectively. The spectra of
dried precursors indicates the characteristic bands in X= 0.6
the range 3200-3600 cm-1 assigned to O-H stretching
vibration of water molecules, while the asymmetrical X= 0.8
and symmetrical vibration bands of CO2- are located
around 1600 cm-1. The bands about 1380 cm -1 are
ascribed to the N-O stretching vibration of NO3-. X= 1.0
FTIR results show that after calcination the
absorption bands related to O-H, CO2-, and N-O are
disappear. The bands appearing around 550 cm-1 and
440 cm-1 are attributed to M-O stretching vibration 20 30 40 50
2 Theta (deg.)
60 70 80
of hexaferrite [22-24].
3.2 X-ray analysis Fig. 2(a) XRD diffractogram of Sr2Cu2-XMnXFe12O22
(x =0.0, 0.6, 0.8, 1.0) hexaferrite powder
Figure 2 (a, b) shows experimental X-ray
diffraction patterns for Sr2Cu2-XMnXFe12O22 (x= 0.0,
0.6, 0.8 and 1.0) samples and a standard pattern for
Y-type hexaferrite respectively. All XRD reflection
peaks are indexed by applying a hexagonal crystal
system and space group P63/mmc (here planes
[0012], [113], [110], [1013], [116], [119], [024],
[0210] [300], [2113], [1025], [220], [3015] used for
prepared samples). Lattice constants a and c of Mn
doped strontium copper hexaferrite samples were
calculated using equation (1)
= (1) Fig. 2(b) Standard XRD pattern of Y- type
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4. Rajshree B. Jotania, Pratiksha A. Patel / International Journal of Engineering Research and
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Vol. 2, Issue 4, July-August 2012, pp.494-498
Table 2. Lattice parameters (a, c) and cell volume Figure. 3 shows SEM micrographs of
(V) of Sr2Cu2-XMnXFe12O22 (x = 0.0, 0.6, 0.8 and 1.0) Sr2Cu2-xMnxFe12O22 (x = 0.0, 0.6, 0.8 and 1.0)
samples hexaferrite samples sintered at 950°C for 4 hrs,
prepared by a chemical coprecipitation method. It is
Sr. Mn Lattice constants observed from SEM images that the grains are non-
uniform and densely distributed over the surface,
No. Content (x) a (Å) c (Å) Volume more over grain size of the compound is found to be
in the range of 300 nm–1.5μm. The SEM
V (Å3) micrographs show that the grain size of the samples
increased distinctly with Mn increases and the
1 0.0 5.695 59.00 1654.23 porosity decreased.
2 0.6 5.695 59.02 1657.13 3.4 Dielectric properties
3 0.8 5.695 59.02 1657.13 The dielectric measurements were carried out over
the frequency range of 100 Hz to 2 MHz at room
4 1.0 5.695 59.00 1657.13
temperature. The variation of dielectric constant
The XRD analysis reveals that all samples produce (real part, ε )׳and dielectric loss (tan δ) with
single Y-type phase and there is no effect of Mn frequency for Sr2Cu2-XMnXFe12O22 (x= 0.8, 1.0)
substitution on phase formation. The results indicate hexaferrite samples are shown in figure (4a) and
that the material has a well defined Y-type ferrite figure 4(b) respectively. It is clear from figure
crystalline phase. Lattice parameters of all four 4(a, b); the dielectric constant (ε )׳as well as
samples are found almost equal (a = 5.690Å, c = dielectric loss tangent (tan δ) decreases with
59.00Å). There is not much effect of Mn substitution increasing measuring frequency. This decrease
on lattice parameters and cell volume because of behavior of (ε )׳and (tan δ) with log frequency can
almost same ionic radii of Cu2+ (0.57Å) and Mn2+ be explained on the basis of the assumption that the
(0.66Å). mechanism of the polarization process in ferrites
[22, 23].
3.3. SEM analysis
18
X=0.8
X=1.0
15
Dielectric constant (real)
12
9
6
2 3 4 5 6 7
Log F
Fig. 4 (a) Frequency dependence of dielectric
constant (real part, ε') of Sr2Cu2-XMnXFe12O22
(x = 0.8, 1.0) hexaferrite samples
The dielectric loss (tan δ) can be expressed in terms
of the real and imaginary parts of the dielectric
constant as
Fig. 3 SEM micrographs of Sr2Cu2-xMnxFe12O22
(3)
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5. Rajshree B. Jotania, Pratiksha A. Patel / International Journal of Engineering Research and
Applications (IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue 4, July-August 2012, pp.494-498
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ACKNOWLEDGEMENTS [25] K. W. Wagner, Amer Phis, 40,1973, 817-855.
The authors are thankful to GUJCOST, [26] C. G. Koops, Phys Rev, 83,1951,121-124.
Gandhinagar, Gujarat, India for providing partial
financial support in the form of minor research
project code no.0401121.
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