This document describes a study on the structural and magnetic characterization of Co2+ substituted nanostructured copper-zinc spinel ferrites. Nano particles of Cu0.61-xCoxZn0.39Fe2O4 were synthesized using a sol-gel auto combustion method. Various characterization techniques were used to analyze the effect of Co2+ substitution on properties like particle size, lattice constant, density, cation distribution, and magnetic properties. It was found that lattice parameter and particle size increased with Co2+ content while density decreased. Cation distribution analysis showed a preference of Co2+ and Cu2+ for octahedral sites and Zn2+ for tetrahedral sites. Magnetic properties like saturation magnetization and coerc
Simple and Effective Method of the Synthesis of Nanosized Fe2O 3particlesIOSR Journals
Abstract: Nanosized Iron oxide is prepared by using precipitation method from iron nitrate and liquid ammonia. Thermal analysis shows that synthesized iron oxide shows some weight loss and oxide undergoing decomposition, dehydration or any physical change from TGA curve we observe that Iron oxide shows stable weight loss above 4000C. In DTA curve also, there is exothermic and endothermic peak. Which shows phase transition, solid state reaction or any chemical reaction occurred during heating treatment. Morphology is observed by scanning electron microscopy (SEM) shows particles are nanosized. Further morphology observation by Transmission Electron Microscopy (TEM) revels that Iron Oxide has the corundum (Al2O3) structure. Magnetic measurements shows that iron oxide has five unpaired electron and strongly paramagnetic character.
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.
A facile method to prepare CdO-Mn3O4 nanocompositeIOSR Journals
CdO-Mn3O4 nanocomposite has been prepared by a simple solvothermal method using a domestic microwave oven. Cadmium acetate, manganese acetate and urea were used as the precursors and ethylene glycol as the solvent. The as-prepared sample was annealed for 1 hour in each case at different temperatures, viz. 100, 200 and 300°C. The as-prepared and annealed samples were characterized by X-ray diffraction and scanning electron microscopic analyses. Results indicate that annealing at 300°C is required to get the sample with high phase purity and homogeneity. The present study indicates that the method adopted can be considered as an economical and scalable one to prepare the proposed nanocomposite with reduced size, phase purity and homogeneity.
Thermal, microstructure and dielectric behavior of la modified bismuth titana...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
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.
Simple and Effective Method of the Synthesis of Nanosized Fe2O 3particlesIOSR Journals
Abstract: Nanosized Iron oxide is prepared by using precipitation method from iron nitrate and liquid ammonia. Thermal analysis shows that synthesized iron oxide shows some weight loss and oxide undergoing decomposition, dehydration or any physical change from TGA curve we observe that Iron oxide shows stable weight loss above 4000C. In DTA curve also, there is exothermic and endothermic peak. Which shows phase transition, solid state reaction or any chemical reaction occurred during heating treatment. Morphology is observed by scanning electron microscopy (SEM) shows particles are nanosized. Further morphology observation by Transmission Electron Microscopy (TEM) revels that Iron Oxide has the corundum (Al2O3) structure. Magnetic measurements shows that iron oxide has five unpaired electron and strongly paramagnetic character.
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.
A facile method to prepare CdO-Mn3O4 nanocompositeIOSR Journals
CdO-Mn3O4 nanocomposite has been prepared by a simple solvothermal method using a domestic microwave oven. Cadmium acetate, manganese acetate and urea were used as the precursors and ethylene glycol as the solvent. The as-prepared sample was annealed for 1 hour in each case at different temperatures, viz. 100, 200 and 300°C. The as-prepared and annealed samples were characterized by X-ray diffraction and scanning electron microscopic analyses. Results indicate that annealing at 300°C is required to get the sample with high phase purity and homogeneity. The present study indicates that the method adopted can be considered as an economical and scalable one to prepare the proposed nanocomposite with reduced size, phase purity and homogeneity.
Thermal, microstructure and dielectric behavior of la modified bismuth titana...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
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.
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.
Fabrication and characterization of conducting polymer compositeijoejournal
The ion conducting polymer composite specimen has been prepared by using Polyvinyl- pyrrolidone
(PVP) and Potassium hydroxide (KOH) using double distilled water as the solvent. The solution cast
techniques was used to prepare the specimens. The main objective of the project is to study structural and
mechanical properties of the polymer composite specimen. The conductivity and micro structure analysis
has been carried out. The results revealed conductivity and hardness of the polymer composite increased
with concentration of the KOH salt
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
Synthesis and analysis of electrical properties of Lead free Ba3Sr2LaTi3V7O30...inventy
Materials of tungsten-bronze (TB) structure belong to an important family of dielectric materials which are well known for their applications in various electrical devices, such as transducers, actuators, capacitors, and ferroelectric random access memory. The TB structure consists of a framework of distorted BO6 octahedral sharing corners in such a way that three different types of interstices (A, B and C) are available for a wide variety of cations occupying in a general formula (A1)2(A2)4(C)4(B1)2(B2)8O30. Our present work deals with the studies of preparation and characterization of the physical properties of a novel single-phase polycrystalline lead-free vanadate having Tungsten Bronze Structure with compound formula Ba3Sr2LaTi3V7O30.The X-ray diffraction analysis confirms the formation of single-phase compound with orthorhombic structure. The effect of temperature (32- 5000C) and frequency (102–106 Hz) on structural and electrical properties were studied using an impedance analyzer. Detailed studies of impedance parameters provide a better understanding of the electrical properties and type of relaxation processes in the material. The bulk resistance is observed to be decreased with rise in temperature showing a typical negative temperature coefficient of resistance (NTCR) behavior.
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.
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, 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.
Ferrites: Ferrites are mixed metal oxides of magnetic nature in which iron is the main component.
In general, ferrites show four different types of crystal structures namely,
1] Ferrospinel Structure.
2] Hexagonal Structure.
3] Garnet Structure.
4] Orthoferrite structure.
We are going to discuss about spinel structure as Co Ni ferrite is a spinel ferrite.
Ferrospinel Structure.
They have the general formula MeFe2O4, where Me is divalent metal ion or a mixture of ions having average valence of two. The unit cell is cubic. The oxygen ions forms a nearly close-packed face centered cubic structure and the metal ions are distributed over tetrahedral and octahedral holes.
Normal ferrites:In which all-divalent metal ions occupy A sites and all the Fe3+ occupy B sites.
e.x. Zn 2+ [Fe23+] O4
Zn 2+ ions have a very low octahedral preference; therefore they enter the A-sites of the lattice, resulting in normal ferrites.
Inverse ferrites:In which all divalent metal ions and half the Fe3+ ions occupy B sites while remaining Fe3+ occupy A sites.
e.x. Fe3+[ Fe3+ Ni2+] O4
Mixed ferrites:In which all divalent metal ions and Fe3+ ions are uniformly distributed over the tetrahedral and octahedral sites.
Co - Ni ferrite is a mixed spinel ferrite, which has general formulae
AII x BII 1-x Fe2O4
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.
Fabrication and characterization of conducting polymer compositeijoejournal
The ion conducting polymer composite specimen has been prepared by using Polyvinyl- pyrrolidone
(PVP) and Potassium hydroxide (KOH) using double distilled water as the solvent. The solution cast
techniques was used to prepare the specimens. The main objective of the project is to study structural and
mechanical properties of the polymer composite specimen. The conductivity and micro structure analysis
has been carried out. The results revealed conductivity and hardness of the polymer composite increased
with concentration of the KOH salt
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
Synthesis and analysis of electrical properties of Lead free Ba3Sr2LaTi3V7O30...inventy
Materials of tungsten-bronze (TB) structure belong to an important family of dielectric materials which are well known for their applications in various electrical devices, such as transducers, actuators, capacitors, and ferroelectric random access memory. The TB structure consists of a framework of distorted BO6 octahedral sharing corners in such a way that three different types of interstices (A, B and C) are available for a wide variety of cations occupying in a general formula (A1)2(A2)4(C)4(B1)2(B2)8O30. Our present work deals with the studies of preparation and characterization of the physical properties of a novel single-phase polycrystalline lead-free vanadate having Tungsten Bronze Structure with compound formula Ba3Sr2LaTi3V7O30.The X-ray diffraction analysis confirms the formation of single-phase compound with orthorhombic structure. The effect of temperature (32- 5000C) and frequency (102–106 Hz) on structural and electrical properties were studied using an impedance analyzer. Detailed studies of impedance parameters provide a better understanding of the electrical properties and type of relaxation processes in the material. The bulk resistance is observed to be decreased with rise in temperature showing a typical negative temperature coefficient of resistance (NTCR) behavior.
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.
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, 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.
Ferrites: Ferrites are mixed metal oxides of magnetic nature in which iron is the main component.
In general, ferrites show four different types of crystal structures namely,
1] Ferrospinel Structure.
2] Hexagonal Structure.
3] Garnet Structure.
4] Orthoferrite structure.
We are going to discuss about spinel structure as Co Ni ferrite is a spinel ferrite.
Ferrospinel Structure.
They have the general formula MeFe2O4, where Me is divalent metal ion or a mixture of ions having average valence of two. The unit cell is cubic. The oxygen ions forms a nearly close-packed face centered cubic structure and the metal ions are distributed over tetrahedral and octahedral holes.
Normal ferrites:In which all-divalent metal ions occupy A sites and all the Fe3+ occupy B sites.
e.x. Zn 2+ [Fe23+] O4
Zn 2+ ions have a very low octahedral preference; therefore they enter the A-sites of the lattice, resulting in normal ferrites.
Inverse ferrites:In which all divalent metal ions and half the Fe3+ ions occupy B sites while remaining Fe3+ occupy A sites.
e.x. Fe3+[ Fe3+ Ni2+] O4
Mixed ferrites:In which all divalent metal ions and Fe3+ ions are uniformly distributed over the tetrahedral and octahedral sites.
Co - Ni ferrite is a mixed spinel ferrite, which has general formulae
AII x BII 1-x Fe2O4
IOSR Journal of Business and Management (IOSR-JBM) is an open access international journal that provides rapid publication (within a month) of articles in all areas of business and managemant and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications inbusiness and management. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Surfactant-assisted Hydrothermal Synthesis of Ceria-Zirconia Nanostructured M...IOSR Journals
CeO2–ZrO2 oxides were prepared by the surfactant-templated method using cetyl trimethyl ammonium bromide (CTAB) as template and modified with chromium nitrate. These were characterized by XRD, FT-IR, TEM, SEM, BET and TPD-CO2. The XRD data showed that as prepared CeO2-ZrO2 powder particles have single phase cubic fluorite structure. HRTEM shows mesoscopic ordering. Average particle size is 12-13 nm as calculated from particle histogram. The nitrogen adsorption/desorption isotherm were classified to be type IV isotherm, typical of mesoporous material. The presence of uni-modal mesopores are confirmed by the pore size distribution which shows pore distribution at around 60 A°. Catalytic activity was studied towards liquid-phase oxidation of benzene.
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.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
Synthesis and charaterization of la1 x srxmno3 perovskite nanoparticlesMai Trần
In recent times perovskite materials are extensively studied and have attracted much attention because they exhibit interesting the properties, showing potential applications in commercial, technical and biomedical. In Vietnam, perovskite materials be of interest research and applications are strong but with major research direction is to go deep into the electrical properties and the magnetic properties. The Lanthanum Strontium manganite is a perovskite-based crystal-structured ceramic material with the formula of La1-xSrxMnO3, where x describes the doping ratio. It has attracted much attention due to its good magnetic, electrical, and catalytic properties and is becoming an attractive possibility material in several biomedical applications, particularly with nano-size. In industry, this material is commonly used in as a cathode material in commercially produced solid oxide fuel cells. In this thesis, we present the Perovskite nanoparticles La1-xSrxMnO3 were successfully synthesized of the nanosize La1-xSrxMnO3 at x = 0; 0.1; 0.2; 0.3 and 0.4 which prepared by a modified sol-gel method. Structure and magnetic properties of them were systematically investigated in dependence on doped Sr ratio x. The structure was investigated by XRD and show slightly changed but magnetic properties varied strongly with changing the doping ratio x. Magnetic properties of samples were studied by Vibrating Sample Mode of Physical Properties Measurement System show at the room temperature, the samples show superparamagnetic properties with high saturated magnetization MS of 57 emu/g which strongly dependents on the doped Sr ratio x.
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
A study of micro structural, magnetic and electrical properties of La-Co-Sm n...IJECEIAES
A Lanthanum (La 3+ ) doped Samarium-Cobalt nanoferrites (La_x,Co_0.2,Sm_0.2,Fe_(2-x) O_4, where x=0.0,0.5,1.0) have been synthesized by sol-gel method in citrate media. Obtained spinal ferrites micro structure properties have been investigated by XRD, FTIR, SEM-EDX, and TEM-SAED techniques. All the samples are nano in size with significant hysteresis. Micro structural analysis by XRD confirms the obtained samples showing the single phase cubic spinal structures with an average crystal size found from 12 nm to 25 nm, while the average particles sizes identified from TEM analysis are ranging from 21.5nm-26.8 nm (~23.4nm) and from 20.5 nm to 28(~26.4nm) nm for x=0.5,1.0. The lattice parameter found to be a= 8.402, 8.423, 8.467Å for the respective values of x= 0.0, 0.05, and 1.0. Electrical properties show increase in dc resistivity with increase in La ion concentration. Finally, it was concluded that the doping of Lanthanum ion (La 3+ ) in the ferrites structure is found to influencing the structural and electrical properties without scarifying the ferromagnetic character.
Structural, Electrical and Magnetotransport properties of La0.7Ca0.2Sr0.1MnO3...IOSR Journals
The sample of manganite perovskite oxide La0.7Ca0.2Sr0.1MnO3 has been prepared by solution combustion synthesis. The synthesized sample has been pelletized and further sintered at 8000C for 8 hours. The XRD pattern reveals that the samples are of single phase nature with orthorhombic structure and the diffraction patterns can be indexed with the pbnm space groups. The crystallite sizes calculated from broadening of XRD peaks using Scherrer’s formula were about 18 nm. Resistivity measurements were performed in the temperature range 2K under 3, 5, 10 and 14 T field using PPMS. Magnetoresistance shows a shift in metal-insulator transition temperature from ~213 K at zero field to ~250 K at 14T. MR value decreases as the temperature increases and at 300 K maximum value of MR is found to be ~ 22% for an applied field of 14 T. MR of ~ 28% is observed at 230 K. MR of ~ 35% is observed at 150 K in an applied field of 14 T and MR has negative sign
Studies On The Cobalt(II) And Copper(II) Complexes Of 2,5-Substituted 1,3,4-T...IOSR Journals
New metal complexes of Co(II),and Cu(II) have been synthesized by reacting metal solutions with the ligand 2,5-substituted 1,3,4-triazoles in alcoholic medium. Molecular formulae of the complexes were determined and are further characterized by IR spectroscopy, magnetic susceptibility and molar conductance studies. The ligand acts as a bidentate ligand co-ordinating through the nitrogen atoms present in the ring.
Structure, microstructure and dielectric study of (ba0.6 sr0.4)(zr0.6ti0.4)o3...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
1 Packing of spheres: Unit cell and description of crystal structure, close
packing of spheres, holes in closed-packed structures.
2 Structure of Metals: Polytypism, structures that are not closed packed, polymorphism of metals, atomic radii of metals, alloys.
3 Ionic solids: Characteristic structures of ionic solids, the rationalization of structures, the energetics of ionic bonding, consequences of lattice enthalpy.
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.
Application of Fe3O4 Sphere Doped with Zn for Enhanced Sonocatalytic Removal ...ijtsrd
Fe3O4 sphere doped Zn were successfully prepared by the simple one pot solvothermal method. Morphology and structure of the as synthesised products was checked through the XRD, SEM, HRTEM techniques. The Fe3¬O4 hollowsphere doped showed the high photocatalytic activity for degradation of hexavalent chromium under visible light irradiation. The effects of reaction conditions such as initial pH, photocatalyst dosage and hexavalent chromium contratentation were also studied systematically. The stability of the catalsyts and and possible catalytic mechanism was also proposed. The results indicate that Fe3O4 sphere doped Zn can be promising catalyst for photo reduction of hexavalent chromium. Xuan Sang Nguyen "Application of Fe3O4 Sphere Doped with Zn for Enhanced Sonocatalytic Removal of Cr (VI) From Aqueous Solutions" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-6 | Issue-1 , December 2021, URL: https://www.ijtsrd.com/papers/ijtsrd47862.pdf Paper URL: https://www.ijtsrd.com/medicine/other/47862/application-of-fe3o4-sphere-doped-with-zn-for-enhanced-sonocatalytic-removal-of-cr-vi-from-aqueous-solutions/xuan-sang-nguyen
Builder.ai Founder Sachin Dev Duggal's Strategic Approach to Create an Innova...Ramesh Iyer
In today's fast-changing business world, Companies that adapt and embrace new ideas often need help to keep up with the competition. However, fostering a culture of innovation takes much work. It takes vision, leadership and willingness to take risks in the right proportion. Sachin Dev Duggal, co-founder of Builder.ai, has perfected the art of this balance, creating a company culture where creativity and growth are nurtured at each stage.
Encryption in Microsoft 365 - ExpertsLive Netherlands 2024Albert Hoitingh
In this session I delve into the encryption technology used in Microsoft 365 and Microsoft Purview. Including the concepts of Customer Key and Double Key Encryption.
Welocme to ViralQR, your best QR code generator.ViralQR
Welcome to ViralQR, your best QR code generator available on the market!
At ViralQR, we design static and dynamic QR codes. Our mission is to make business operations easier and customer engagement more powerful through the use of QR technology. Be it a small-scale business or a huge enterprise, our easy-to-use platform provides multiple choices that can be tailored according to your company's branding and marketing strategies.
Our Vision
We are here to make the process of creating QR codes easy and smooth, thus enhancing customer interaction and making business more fluid. We very strongly believe in the ability of QR codes to change the world for businesses in their interaction with customers and are set on making that technology accessible and usable far and wide.
Our Achievements
Ever since its inception, we have successfully served many clients by offering QR codes in their marketing, service delivery, and collection of feedback across various industries. Our platform has been recognized for its ease of use and amazing features, which helped a business to make QR codes.
Our Services
At ViralQR, here is a comprehensive suite of services that caters to your very needs:
Static QR Codes: Create free static QR codes. These QR codes are able to store significant information such as URLs, vCards, plain text, emails and SMS, Wi-Fi credentials, and Bitcoin addresses.
Dynamic QR codes: These also have all the advanced features but are subscription-based. They can directly link to PDF files, images, micro-landing pages, social accounts, review forms, business pages, and applications. In addition, they can be branded with CTAs, frames, patterns, colors, and logos to enhance your branding.
Pricing and Packages
Additionally, there is a 14-day free offer to ViralQR, which is an exceptional opportunity for new users to take a feel of this platform. One can easily subscribe from there and experience the full dynamic of using QR codes. The subscription plans are not only meant for business; they are priced very flexibly so that literally every business could afford to benefit from our service.
Why choose us?
ViralQR will provide services for marketing, advertising, catering, retail, and the like. The QR codes can be posted on fliers, packaging, merchandise, and banners, as well as to substitute for cash and cards in a restaurant or coffee shop. With QR codes integrated into your business, improve customer engagement and streamline operations.
Comprehensive Analytics
Subscribers of ViralQR receive detailed analytics and tracking tools in light of having a view of the core values of QR code performance. Our analytics dashboard shows aggregate views and unique views, as well as detailed information about each impression, including time, device, browser, and estimated location by city and country.
So, thank you for choosing ViralQR; we have an offer of nothing but the best in terms of QR code services to meet business diversity!
UiPath Test Automation using UiPath Test Suite series, part 3DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 3. In this session, we will cover desktop automation along with UI automation.
Topics covered:
UI automation Introduction,
UI automation Sample
Desktop automation flow
Pradeep Chinnala, Senior Consultant Automation Developer @WonderBotz and UiPath MVP
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
Accelerate your Kubernetes clusters with Varnish CachingThijs Feryn
A presentation about the usage and availability of Varnish on Kubernetes. This talk explores the capabilities of Varnish caching and shows how to use the Varnish Helm chart to deploy it to Kubernetes.
This presentation was delivered at K8SUG Singapore. See https://feryn.eu/presentations/accelerate-your-kubernetes-clusters-with-varnish-caching-k8sug-singapore-28-2024 for more details.
The Art of the Pitch: WordPress Relationships and SalesLaura Byrne
Clients don’t know what they don’t know. What web solutions are right for them? How does WordPress come into the picture? How do you make sure you understand scope and timeline? What do you do if sometime changes?
All these questions and more will be explored as we talk about matching clients’ needs with what your agency offers without pulling teeth or pulling your hair out. Practical tips, and strategies for successful relationship building that leads to closing the deal.
GDG Cloud Southlake #33: Boule & Rebala: Effective AppSec in SDLC using Deplo...James Anderson
Effective Application Security in Software Delivery lifecycle using Deployment Firewall and DBOM
The modern software delivery process (or the CI/CD process) includes many tools, distributed teams, open-source code, and cloud platforms. Constant focus on speed to release software to market, along with the traditional slow and manual security checks has caused gaps in continuous security as an important piece in the software supply chain. Today organizations feel more susceptible to external and internal cyber threats due to the vast attack surface in their applications supply chain and the lack of end-to-end governance and risk management.
The software team must secure its software delivery process to avoid vulnerability and security breaches. This needs to be achieved with existing tool chains and without extensive rework of the delivery processes. This talk will present strategies and techniques for providing visibility into the true risk of the existing vulnerabilities, preventing the introduction of security issues in the software, resolving vulnerabilities in production environments quickly, and capturing the deployment bill of materials (DBOM).
Speakers:
Bob Boule
Robert Boule is a technology enthusiast with PASSION for technology and making things work along with a knack for helping others understand how things work. He comes with around 20 years of solution engineering experience in application security, software continuous delivery, and SaaS platforms. He is known for his dynamic presentations in CI/CD and application security integrated in software delivery lifecycle.
Gopinath Rebala
Gopinath Rebala is the CTO of OpsMx, where he has overall responsibility for the machine learning and data processing architectures for Secure Software Delivery. Gopi also has a strong connection with our customers, leading design and architecture for strategic implementations. Gopi is a frequent speaker and well-known leader in continuous delivery and integrating security into software delivery.
Smart TV Buyer Insights Survey 2024 by 91mobiles.pdf91mobiles
91mobiles recently conducted a Smart TV Buyer Insights Survey in which we asked over 3,000 respondents about the TV they own, aspects they look at on a new TV, and their TV buying preferences.
Observability Concepts EVERY Developer Should Know -- DeveloperWeek Europe.pdfPaige Cruz
Monitoring and observability aren’t traditionally found in software curriculums and many of us cobble this knowledge together from whatever vendor or ecosystem we were first introduced to and whatever is a part of your current company’s observability stack.
While the dev and ops silo continues to crumble….many organizations still relegate monitoring & observability as the purview of ops, infra and SRE teams. This is a mistake - achieving a highly observable system requires collaboration up and down the stack.
I, a former op, would like to extend an invitation to all application developers to join the observability party will share these foundational concepts to build on:
Transcript: Selling digital books in 2024: Insights from industry leaders - T...BookNet Canada
The publishing industry has been selling digital audiobooks and ebooks for over a decade and has found its groove. What’s changed? What has stayed the same? Where do we go from here? Join a group of leading sales peers from across the industry for a conversation about the lessons learned since the popularization of digital books, best practices, digital book supply chain management, and more.
Link to video recording: https://bnctechforum.ca/sessions/selling-digital-books-in-2024-insights-from-industry-leaders/
Presented by BookNet Canada on May 28, 2024, with support from the Department of Canadian Heritage.
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
Essentials of Automations: Optimizing FME Workflows with ParametersSafe Software
Are you looking to streamline your workflows and boost your projects’ efficiency? Do you find yourself searching for ways to add flexibility and control over your FME workflows? If so, you’re in the right place.
Join us for an insightful dive into the world of FME parameters, a critical element in optimizing workflow efficiency. This webinar marks the beginning of our three-part “Essentials of Automation” series. This first webinar is designed to equip you with the knowledge and skills to utilize parameters effectively: enhancing the flexibility, maintainability, and user control of your FME projects.
Here’s what you’ll gain:
- Essentials of FME Parameters: Understand the pivotal role of parameters, including Reader/Writer, Transformer, User, and FME Flow categories. Discover how they are the key to unlocking automation and optimization within your workflows.
- Practical Applications in FME Form: Delve into key user parameter types including choice, connections, and file URLs. Allow users to control how a workflow runs, making your workflows more reusable. Learn to import values and deliver the best user experience for your workflows while enhancing accuracy.
- Optimization Strategies in FME Flow: Explore the creation and strategic deployment of parameters in FME Flow, including the use of deployment and geometry parameters, to maximize workflow efficiency.
- Pro Tips for Success: Gain insights on parameterizing connections and leveraging new features like Conditional Visibility for clarity and simplicity.
We’ll wrap up with a glimpse into future webinars, followed by a Q&A session to address your specific questions surrounding this topic.
Don’t miss this opportunity to elevate your FME expertise and drive your projects to new heights of efficiency.
Quantum Computing: Current Landscape and the Future Role of APIs
F0363341
1. IOSR Journal of Applied Physics (IOSR-JAP)
e-ISSN: 2278-4861.Volume 3, Issue 6 (May. - Jun. 2013), PP 33-41
www.iosrjournals.org
www.iosrjournals.org 33 | Page
Structural and magnetic characterization of Co2+
substituted
nano structured Copper-Zinc spinel ferrite
Sindhu S1
, D. D. Birajdar2
1
GND Engineering College, Bidar, Karnataka State, India
2
B.S.S. Arts,Science and Commerce college Makani, Osmanabad (M.S.), India
Abstract : Nano particles of Cu0.61-xCoxZn0.39Fe2O4 (0 ≤ x ≤ 0.5) synthesized through sol-gel auto combustion
method. Nitrates of elements and citric acid are used as starting materials. X-ray Diffraction, Thermo
Gravimetric Analysis and Vibrating Sample Magnetometer are used to analyze the properties. Effect of
variation in the Co substitution and its impact on particle size, lattice constant, density, cation distribution,
ferritization temperature, associated water content, magnetic properties like saturation magnetization(MS),
coercivity(HC) and remanent magnetization(Mr) is observed. Lattice parameter increases with increasing Co+2
concentration whereas X-ray density, bulk density decreases with the Co+2
content. In Cation distribution the
Co and Cu ion show preference towards octahedral B-site, Zn occupy A site whereas Fe occupy both A and B
site. Cation redistribution takes place for x > 0.3. Saturation magnetization increases from (x ≤ 0.3). For x >
0.3, Ms decreases suggesting that significant canting exists at B site. However, coercivity, magnetocrystalline
anisotropy and remanant magnetization increases with the Co2+
substitution.
Keywords: Coercivity(HC), Remanent and Saturation Magnetization , Sol-gel synthesis, Thermo Gravimetric
Analysis and Vibrating Sample Magnetometer, X-ray Diffraction.
I. Introduction
Co2+
substituted Cu0.61-xCoxZn0.39Fe2O4 ferrites are commercially important magnetic materials and play
an important role in the production of magnetic recording media.The cation distribution in CuFe2O4 copper
ferrite can be represented by formula (Cu2+
x+Fe3+
1-x)A
[Cu2+
1-x+Fe3+
1+x]B
O4. The parameter of inversion is (0 ≤ x
≤ 0.5). When the spinel is synthesized using classical ceramic technologies (high temperature treatment of the
initial oxides of the metal cations) with strict stoichiometry (x = 1), it has tetragonal structure with crystal cell
parameters a = 8.20 and c = 8.60; c/a = 1.05 [1]. The c/a ratio can be changed via decreasing the copper
concentration, or alternatively, by temperature treatments. Yokoyama et al. [2] observed changes in the crystal
structure of nanosized CuFe2O4 powders obtained by co-precipitation and subsequent annealing. According to
some other authors [3] a = 8.24, c = 8.68, but c/a is again 1.05. The structure of CuFe2O4 is considered as that of
a tetragonally deformed spinel stretched along the (0 1 1) direction. They proved that the copper spinel is cubic
at temperatures below 300°C and tetrahedral over 400°C. Further Co ferrite shows good magnetostrictive
properties, magnetocrystalline anisotropy, high coercivity and moderate saturation magnetization among all the
ferrite family [10]. Therefore, by keeping this composition in our mind, we have proposed the studies on
structural analysis, cation distribution and magnetic properties of nano-size Cu0.61-xCoxZn0.39Fe2O4 (0 ≤ x ≤ 0.5)
by sol-gel method.
II. Experimental:
2.1 Preparation method:
Sol-gel auto-combustion method is a novel method of preparing nano-materials [11] by which
nanocrystalline powder of Cu0.61-xCoxZn0.39Fe2O4 (0 ≤ x ≤ 0.5) is prepared. It can save energy and avoid
agglomeration during the calcinations at high temperature. A.R. grade citric acid (C6H8O7)·H2O, copper nitrate
(Cu(NO3)2·3H2O, zinc nitrate (Zn(NO3)2·6H2O, cobalt nitrate (Co(NO3)2·3H2O and ferric nitrate
Fe(NO3)3·9H2O were used as starting materials. The metal nitrates were dissolved in a minimum amount of
double distilled water to get a clear solution and ammonia solution was slowly added to maintain the pH. The
mixed solution was kept on to a hot plate with continuous stirring. The solution became viscous and finally
formed a very viscous brown gel. When finally all water molecules were removed from the mixture, the viscous
gel began frothing. After few minutes, the gel automatically ignited and burnt with glowing flints. The auto-
combustion was completed within a minute, yielding the brown-colored ashes termed as a precursor. The
powder which is thus prepared, then annealed at 600 0
C for 4 hours.
2.2 Structural and magnetic characterization:
The dried gels were characterized by Thermo gravimetric analysis and differential thermal analysis at a
heating rate of 100
C/min in air atmosphere. The samples were powdered for X-ray investigations. Magnetic
2. Structural and magnetic characterization of Co2+
substituted nano structured Copper-Zinc spinel
www.iosrjournals.org 34 | Page
measurements were performed using the commercial PARC EG&G vibrating sample magnetometer VSM 4500.
Hysteresis curve loops were measured at room temperature with maximum applied magnetic fields. Magnetic
field sweep rate was 5 Oe/s for all measurements. Hence measurement of hysteresis loops with maximum field
of 0.7 T took about 2 hours. The samples prepared in powder form were fixed in paraffin in order to exclude the
motion of powder in a measuring cap.
III. Results and discussion:
3.1 Structural properties:
The experimental observation showed that the nitrate–citrate gels with all three molar ratios of metal
nitrates to citric acid exhibited self-propagating combustion behavior. It was also observed that the combustion
rate is associated with the ratio of nitrates of citric acid. The TGA of the mid sample x = 0.3 decomposing in air
atmosphere in the temperature range 20 to 7000
C with a heating rate of 10 0
C/min is shown in Fig. 1.
The observed weight loss below 1000
C of x = 0.3 sample for Co is attributed to the loss of physically or
chemically absorbed OH groups. The weight loss around 350 0
C, which is ascribed to the vaporization of
absorbed water. The third weight loss around 350 to 600 0
C, which is associated with the residual organic matter
including citric acid. The weight loss below 600 0
C is due to the loss of absorbed water and the decomposition
of organic derivatives. Final weight loss above 600 0
C, due to weight loss of as received powder. The end-
products after decomposition were identified as single spinel phase Cu–Co–Zn ferrite. From the analysis of
their recorded XRD patterns (Fig. 2).
This proves the simultaneous completion of decomposition process of oxalate complex and ferritization. The
XRD patterns exhibit peaks corresponding to typical Cu–Co–Zn ferrites and the absence of any other impurity
phase. Substitution of Cu by Co increases the overall crystallinity of the spinel phase and all the peaks are
3. Structural and magnetic characterization of Co2+
substituted nano structured Copper-Zinc spinel
www.iosrjournals.org 35 | Page
indexed as reported on ASTM cards (cards 1-1121 and 3-0864). The variation of lattice constant with
composition x is shown in Fig. 3.
It is clear from Fig. 3 that lattice constant decreases with increase in x for x = 0.1. For x > 0.1 lattice constant
increases with composition x. Generally in a solid solution series, linear increase or decrease of lattice constant
within the miscibility range with composition is observed [12]. This may results into initial decrease in lattice
constant up to x = 0.1 beyond which it increases. This nonlinear behavior of lattice constant suggests that the
ferrite system is not completely normal or inverse. In the present series, Cu0.61-xCoxZn0.39Fe2O4 (0 ≤ x ≤ 0.5)
smaller Cu2+
(0.72Å) ions are replaced by larger Co2+
(0.745Å) [13]. Doping Co2+
ions in a spinel type structure
will induce uniform strain in the lattice as the material is elastically deformed. This effect causes the lattice
plane spacing to change and the diffraction peaks shift to a lower 2 position. Since each primitive unit cell of
the spinel structure contains eight molecules, the X-ray density, dX’ was determined according to the following
relation [14] 3
8
)(
aN
M
Ferritedx
where M is molecular weight of the particular ferrite, N is the
Avogadro’s number and a3
is the volume of the cubic unit cell and are shown in Fig.4.
From Fig. 4, it is observed that X-ray density ‘dx’ decreases with addition of Co2+
ion content, which may be
attributed to the ionic radii of constituent ions causing decrease in lattice parameter and the molecular weight of
cobalt ferrite (234.625) is lower than copper ferrite (239.23). The bulk density ‘dB’ of the specimens has been
determined by the hydro-static method. The values of the bulk density are shown in Fig. 4. The bulk density was
found to decrease with Co content x. These measurements show densities decreases with Co2+
substitution
which in accordance with the densities of pure Cu and Co ferrites, 8.95gm/cm3
and 5.29gm/cm3
, respectively.
4. Structural and magnetic characterization of Co2+
substituted nano structured Copper-Zinc spinel
www.iosrjournals.org 36 | Page
The broad peaks are seen in XRD indicates the nano particle size of the ferrite formed due to sol-gel
preparation. It is also evident from the crystallite size of 25-34 nm for all samples estimated from the most
intense peak (311) using the Scherrer equation, Dhkl = 0.9λ/Bcosθ, [15] where Dhkl, λ, B, and θ are the volume-
averaged particle diameter, X-ray wavelength, full width at half maximum (FWHM), and diffraction angle,
respectively.
The present results in fig.5 depict that the increasing concentration of cobalt Co2+
decreases with the particle
size. This was probably due to the reaction condition, which favored the formation of new nuclei preventing
further growth of particles when the Co concentration was increased. This may be due to migration of small
number of Co2+
ions in the midst of Co3+
ions in B-sites. This observation is similar to that of Caltun et. al. [16]
for Co-Mn ferrite. The hopping length for tetrahedral A-site (LA) and octahedral B-sites (LB) are calculated
using the values of lattice constant. The variation of hopping lengths with Co content x is shown in Fig. 6 & 7.
It is observed from Fig. 6 & 7 that the distance between the magnetic ions (hopping length) increases as Co
content x increases. Using the experimental values of lattice constant ‘a’ and oxygen positional parameter ‘u’
and substituting it into equations discussed elsewhere [17]. Tetrahedral and octahedral bond length (dAx and dBx),
tetrahedral edge, shared and unshared octahedral edge (dAXE, dBXE and dBXEU) were calculated and the values are
given in Table 1
5. Structural and magnetic characterization of Co2+
substituted nano structured Copper-Zinc spinel
www.iosrjournals.org 37 | Page
Table 1
Tetrahedral bond (dAx), Octahedral bond (dBx), Tetra edge (dAxE) and octaedge (Shared dBXE and
unshared dBXEU). The error estimates is (± 0.002 Å).
It is observed that the allied parameter increases as from its starting value with Co content x increases. This
could be related to the larger radius of Co2+
ions as compared to Cu3+
ions and the site occupancy of the
constituent ions in the present ferrite system.
3.2 Cation distribution:
The cation distribution in the present system was obtained from the analysis of X-ray diffraction
patterns. In this method the observed intensity ratios were compared with the calculated intensity ratios. In the
present study Bertaut method [18] is used to determine the cation distribution. This method selects a few pairs of
reflections according to the expression
.
'''
.
.
'''
.
Calc
lkh
Calc
hkl
Obs
lkh
Obs
hkl
I
I
I
I
(1)
where,
.Obs
hklI and
.Calc
hklI are the observed and calculated intensities for reflection (hkl), respectively. If an
agreement factor (R) is defined as in Eq. (2), the best-simulated structure which matches the actual structure of
the sample will lead to a minimum value of R and the corresponding cation distribution is obtained for each hkl
and lkh '' reflection pair considered.
.
'''
.
.
'''
.
Calc
lkh
Calc
hkl
Obs
lkh
Obs
hkl
I
I
I
I
R (2)
The intensities of these are nearly independent of the oxygen parameters. To determine the cation
distribution and its variation with composition, it is necessary to calculate for each composition the above
mentioned intensity ratios expected for given arrangements of the cations and compare them with the
experimental values.
Phklhkl LPFI
2
(3)
where, F is structure factor, P is multiplicity factor, LP the Lorentz polarization factor and
2cossin
2cos1
2
2
PL (4)
The atomic scattering factor for various ions was taken from the literature [19]. It The cation distribution for
each concentration and the site preferences of cations distributed among tetrahedral A-site and octahedral B-site
showing the fraction of Cu2+
and Fe3+
ions on either sites are listed in Table 2.
Table 2
Cation distribution of Cu0.61-xCoxZn0.39Fe2O4
X
Cation distribution
A-site B-site
0.0 (Zn0.39Fe0.61) [Cu0.61Fe1.39] O4
0.1 (Cu0.06Zn0.39Fe0.55) [Cu0.45Co0.1Fe1.45] O4
0.2 (Cu0.075Zn0.39Fe0.535) [Cu0.425Co0.2Fe1.375] O4
0.3 (Cu0.08Zn0.39Fe0.53) [Cu0.32Co0.3Fe1.38] O4
0.4 (Cu0.09Co0.05Zn0.25Fe0.61) [Cu0.21Co0.35Zn0.05Fe1.39] O4
0.5 (Cu0.1Co0.09Zn0.21Fe0.60) [Cu0.1Co0.41Zn0.09Fe1.40] O4
X
dAX
(Å)
dBX
(Å)
Tetra edge (Å) Octa edge (Å)
dAXE dBXE dBXEU
0 1.907 2.054 3.113 2.831 2.981
0.1 1.904 2.050 3.106 2.820 2.973
0.2 1.905 2.051 3.109 2.825 2.974
0.3 1.907 2.053 3.113 2.828 2.978
0.4 1.909 2.055 3.116 2.831 2.982
0.5 1.911 2.057 3.121 2.835 2.985
6. Structural and magnetic characterization of Co2+
substituted nano structured Copper-Zinc spinel
www.iosrjournals.org 38 | Page
The variation of mean ionic radius of the A-site (rA) and of the B-site (rB) with Co is shown in Fig. 8 &
9. The rA increases up to x ≤ 0.3, this is due the increase in migration of larger Cu2+
(0.72 Å) ions from B site to
A site which replaces smaller Fe3+
(0.67 Å) ions at B site.
0A R3a
4
1
ur
(5)
Fig. 10 shows the increase in the theoretical value of lattice constant ath with Co cotent &Fig. 11 shows
decreasing value of oxygen positional parameter ‘u’ from 0.387 to 0.386 (Å). However, in the present work
u>0.375 may be due to anion displacement from the ideal situation so that it forms a expanded tetrahedral
interstices. The lattice disturbance is confirmed from the data for lattice constant and the oxygen positional
parameter u. The theoretical lattice parameter ‘ath’ was calculated using the values of tetrahedral and octahedral
reading (rA, rB) and is given by the following relation,
0B0Ath Rr3Rr
33
8
a (6)
where, rA and rB are radii of tetrahedral (A) site and octahedral [B] site, R0 is radius of oxygen i.e. (R0= 1.32 Å).
It is noticed that ath is higher than a at lower concentration of Co2+
, and becomes closer at higher Co content.
The deviation may be due to the formation of Co3+
in tetrahedral sites which has lower radius than Co2+
.
7. Structural and magnetic characterization of Co2+
substituted nano structured Copper-Zinc spinel
www.iosrjournals.org 39 | Page
3.3 Magnetic properties:
Room temperature hysteresis loops with the field of 7 kOe, for all the samples are shown in Fig. 12. Fig. 12
shows the variation of saturation magnetization with Co2+
content x. These plots show that an increase in Co2+
doping yields monotonic increase in the saturation magnetization of Cu-Co-Zn ferrite (for x ≤ 0.3), which may
be due to the substitution of Cu2+
ions by Co2+
ions on the octahedral sites. The magnetic moment µB per ion for
Co2+
ions (3 µB) is more than that for Cu2+
(1 µB). Therefore, the increasing Co2+
concentration (x) on the
octahedral sites may result in an increasing magnetic moment per formula of and Cu0.61-xCoxZn0.39Fe2O4 (0 ≤ x ≤
0.5) an enhancement of magnetization .Magnetization decreases for x > 0.3 this may be due to the following
fact.
As the percentage of Co2+
increases from 0.3 to 1, the Ms value gets decreased. Similarly, an increase
of a and or b shift the magnetization value to lower side explains low Ms value for x ≤ 0.3. The net magnetic
moment (nB Cal.) is given by the sum of the magnetic moments of A and B sublattices, i.e., MS = MB-MA. For
Co2+
substituted Cu-Zn ferrite, Co+2
substitution for Cu2+
ions at B site, leading to a increase in the B site
sublattice magnetization. Moreover, the Fe3+
(5µB) ions are replaced by less magnetic Cu2+
(1µB) ions of A-site,
leading to a decrease in the A site sublattice magnetization, which leads to a increase in the net magnetization.
For example, we use the known magnetic moments for Cu2+
(1µB), Zn2+
(0µB), and Fe3+
(5µB). In this study, the
cationic distribution, Zn2+
(0µB) ions are non-magnetic and do not contribute to the sublattice magnetization.
For Cu0.61-xCoxZn0.39Fe2O4. ABS MMM = (0.7 × 5)µB- (0.7 × 1 + 1.3 × 5)µB = 3.7 µB. The observed
magnetic moment (nB Obs.) per formula unit in Bohr magneton (µB) was calculated by using the relation [30].
5585
Mwt.Mol
n S
B
where nB is the magnetic moment of the samples expressed in Bohr magneton. Ms is the saturation
magnetization. The values of (nB) are shown in Fig. 12 & 13.
8. Structural and magnetic characterization of Co2+
substituted nano structured Copper-Zinc spinel
www.iosrjournals.org 40 | Page
Both of them increase up to x = 0.3 and then decrease with the increase in Co concentration. Similar reports for
saturation magnetization have been quoted by others [31].
nB = (6 + x) cos αY−K −5 (1− x) (5)
where x represents Co concentration. The values of Y–K angles are demonstrated in Fig. 10. It increases
exponentially with the increase in Co concentration for x > 0.3. This shows that in the present system of ferrites,
randomness increases as Co is substituted in these Cu ferrites and shows a significant departure from Néel
collinear model. The coercive force (Hc) is an independent parameter, which can be altered by
magnetocrystalline anisotropy, particle size, porosity, heat deformation and hence is not dependent on saturation
magnetization. In this study, the coercive forces tend to rise in increasing Co2+
substitution content, in which the
values of coercive force varied in the range 100.21- 268.83 Oe (Fig. 15 & 16)
The strong magnetocrystalline anisotropy of the octahedral Co2+
ions contributed to the strengthening of the
coercive force. There will be a dependence of anisotropy constant K on the Co2+
ion concentration x, which can
be evaluated by using the relation [37]
S
C
M
K98.0
H
For all the concentrations Co2+
ions system may be considered as isolated Because of the strong dependence of
the anisotropy on the location of cations, the measurement of coercivity is a sensitive probe for following cation
migrations after increasing Co2+
ions. Furthermore, the distortion of the unit cell, the directional order of the
octahedral Co2+
ions, and the shape anisotropy of the particles combine to render Cu0.61-xCoxZn0.39Fe2O4 ferrite
powders to become hard magnetic materials with increasing coercivities [38]. The remanent magnetization (Mr)
is also an independent parameter since it is not wholly dependent on saturation magnetization (Ms) and coercive
force (Hc). The values of remanent magnetization increases from 8.11 to 19.67 emu/gm. Our samples have
significance in magnetic recording media, because recording media requires a high saturation magnetization and
a moderately high coercivity [39].
IV. Conclusions:
The main conclusions that are derived from the obtained results are:
Copper nitrate, Cobalt nitrate, zinc nitrate and interacted with ferric nitrate at temperatures starting from
600 0
C yielding Cu0.61-xCoxZn0.39Fe2O4.
The particle size estimated showed a decreasing trend with the increase in the Co concentration though the
preparation condition was identical for all the samples.
The cation distribution suggests that Co2+
and Cu+2
both have strong preference towards octahedral B-site,
Zn2+
also occupy B site by very small amount, whereas Fe3+
occupy both A and B site.
Magnetic measurements shows an increase in Ms value for x ≤ 0.3 and for x > 0.3 shows decreasing trend
which suggests, redistribution of cations is occurred at higher Co2+
substitution, which ultimately result
preferential filling of Co and/or Cu ions in the tetrahedral site.
Samples have significance in magnetic recording media.
9. Structural and magnetic characterization of Co2+
substituted nano structured Copper-Zinc spinel
www.iosrjournals.org 41 | Page
References:
[1] H.H. Hamdeh, J.C. Ho, S.A. Oliver, R.J. Willey, G. Oliver, G. Busca, J. Appl. Phys. 81 (1997) 1851.
[2] M. Yokoyama, A. Nakamura, T. Sato, K. Haneda, J. Magn. Soc. Jpn. 22 (Suppl. S1) (1998) 243.
[3] G. Nicoara, D. Fratiloiu, M. Nogues, J.L. Dormann, F. Vasiliu, Mater. Sci. Forum 235–238 (1997) 145.
[5] R. Kulkarni, V.U. Patil, J. Mater. Sci. 17 (1982) 843.
[6] N.S. Satyamurthy et.al Phys. Rev. 181 (2) (1969) 969.
[7] Muhammad Ajmal, Asghari Maqsood, J. Alloys Compd. 460 (2008) 54
[10] B.G. Toksha, Sagar E. Shirsath, S.M. Patange, K.M. Jadhav, Solid State Commun. 147(2008) 479.
[11] Selvan RK, Augusin CO, Berchmans LJ, Saraswathi R. Mater Res Bull 2003;38:41.
[12] C. G. Whinfrey, D. W. Eckort, A. Tayber, J. Am. Chem. Soc. 82 (1960) 2695
[13] N. Izaoumen, M. Cherrab, K. Rissouli, K. Benkhouja, K. Jaafari and M. Fahad, J. Phys. IV France 123 (2005) 291
[14] R.C. Kambale, P.A. Shaikh, S.S. Kamble, Y.D. Kolekar, Journal of Alloys and Compounds 478 (2009) 599
[15] V. G. Patil, Sagar E. Shirsath, S. D. More, S. J. Shukla, K. M. Jadhav, J. Alloys. Compd. (2009) In press.
[16] Ovidiu Caltun, G.S.N. Rao, K.H. Rao, B.P. Rao, Ioan Dumitru, Choung-Oh Kim, CheolGi Kim, J. Magn. Magn. Mater. 316
(2007) e618–e620.
[17] S. M. Patange, Sagar E. Shirsath, B. G. Toksha, S. S. Jadhav, S. J. Shukla, K. M. Jadhav, Appl. Phys. A: 95 (2009) 429.
[18] L. Weil, E. F. Bertaut, L. Bochirol. J. Phys. Radium, 11 (1950) 208.
[19] B.D. Cullity, Introduction to Magnetic Materials, Addison-Wesley, MA, 1972, p. 141.
[20] J.B. Goodenough, A.L. Loeb, Phys. Rev. 98 (1955) 391.
[21] H.N. Ok, Y.K. Kim, Phys. Rev. B 36 (1987) 5120.
[22] J. Janicki, J. Pietrzak, A. Poresbska, J. Suwalski, Phys. Stat. Sol. (a) 72 (1982) 92.
[23] H.L. Schl.afer, G. Gliemann, Einf.uhrung in die Ligandenfeldtheorie, Akademische Verlagsgesellschaft, Frankfurtam Main, 1967.
[24] M.D. Sturge, in: F. Seitz, D. Turnbul, H. Ehrenreich (Eds.), Solid State Physics, Vol. 20, Academic Press, New York, 1967.
[25] J.W. Vrewey, E.L. Heilmann, J. Chem. Phys. 15 (4) (1947) 174–180.
[26] T. Abbas, Y. Khan, M. Ahmad, S. Anwar, Solid State Comm. 82 (9) (1992) 701–703.
[27] G. Fagherazzi, F. Garbassi, J. Appl. Crystallogr. 5 (1977) 18.
[28] C.O. Arean, J.L.R. Blanco, J.M.R. Gonzalez, M.C.T. Fernandez, J. Mater. Sci. Letts. 9 (1990) 229
[29] C.O. Arean, E.G. Diaz, J.M.R. Gonzalez, M.A.V. Garcia, Solid State Comm. 77 (1988) 275.
[30] J. Smit, H.P.T. Wijn, Ferrites, Wiley, New York, 1959.
[31] S.I. Patil and Raka V. Dabhade, IEEE Trans. Mang. 30 (1994) 4915
[32] L. Néel. C. R. Acad. Sci. Paris 230 (1950) 375.
[33] O. Caltun, H. Chirac, Lupu., I. Dumitru., P.B. Rao, J. Opto. Adv. Mater. 9 (2007) 1158.
[34] Y. Yafet, C. Kittel, Phys. Rev. 90 (1952) 295.
[35] S. S. Bellad, R. B. Pujar, B. K. Chougule, Mater. Chem. Phys. 52 (1998) 166.
[36] S. S. Jadhav, Sagar E. Shirsath, B. G. Toksha, S. J. Shukla, K. M. Jadhav, Chin. J. Chem. Phys. 21, 381 (2008).
[37] H. Yangy, Z.Wangy, L. Songy, J. Phys. D: Appl. Phys. 29 (1996) 2574.
[38] Ph. Tailhades, C. Villette, and A. Rousset, G. U. Kulkarni, K. R. Kannan, and C. N. R. Rao, M. Lenglet, J. Sol. State. Chem. 141,
(1998) 56
[39] Y.L. Li, G.D. Li, Physics of Ferrite, Publishing House of Electronics Industry of Science, Beijing, 1978, p. 514