scholarly journals Eco-Friendly Synthesis, TEM and Magnetic Properties of Co-Er Nano-Ferrites

2021 ◽  
Vol 12 (1) ◽  
pp. 910-928
Keyword(s):  
Particle Size ◽  
Magnetic Properties ◽  
Crystallite Size ◽  
Rietveld Analysis ◽  
Sem Analysis ◽  
Tem Analysis ◽  
Edax Analysis ◽  
Cobalt Ferrites ◽  
Auto Combustion ◽  
Structural And Magnetic Properties

Synthesis of Cobalt-Erbium nano-ferrites with formulation CoErxFe2-xO4 (x = 0, 0.005, 0.010, 0.015, 0.020, 0.025, and 0.030) using technique of citrate-gel auto-combustion was done. Characterization of prepared powders was done using XRD, EDAX, FESEM, TEM, AFM, and FTIR spectroscopy, VSM: magnetic properties, respectively. XRD Rietveld Analysis, SEM, TEM, and EDAX analysis studied spectral, structural, and magnetic properties. XRD pattern of CEF nanoparticles confirms single-phase cubic spinal structure. The structural variables are given by lattice constant (a), lattice volume (v), the average crystallite size (D) and X-ray density (dx), bulk density (d), porosity (p), percentage of pore space (P%), surface area (s), strain(ε), dislocation density (δ), along with ionic radii, bond length and hoping length were calculated. SEM and TEM results reveal the homogeneous nature of particles accompanied by clusters having no impurity pickup. TEM analysis gives information about the particle size of nanocrystalline ferrite, while EDAX analysis confirms elemental composition. The emergence of two arch-shaped frequency bands (ν_1 and〖 ν〗_2) that represent vibrations at the tetrahedral site (A) and octahedral site(B) was indicated by spectra of FTIR. The XRD Rietveld analysis confirms crystallite size lying between 20.84 nm-14.40 nm, while SEM analysis indicates the formation of agglomerates and TEM analysis indicates particle size ranging between 24nm-16 nm. The XRD Rietveld analysis confirms crystallite size lying between 20.84nm-14.40nm, while SEM analysis indicates the formation of agglomerates and TEM analysis indicates particle size ranging between 24 nm - 16 nm. The magnetization measurements indicated that increasing Er3+ content in cobalt ferrites decreases magnetization from 60emu/g to 42emu/g while coercivity decreases (18990) as compared to CoFe2O4 (18998) in cobalt ferrites with doping. The present study investigates the effect of different compositions of Er3+ replaced for Fe on structural and magnetic properties of cobalt ferrites.

scholarly journals Crystal Chemistry, Rietveld Analysis, Structural and Electrical Properties of Cobalt-Erbium Nano-Ferrites

2021 ◽  
Author(s):  
Edapalli Sumalatha ◽  
Dachepalli Ravinder ◽  
Nyathani Maramu ◽  
Shubha ◽  
Butreddy Ravinder Reddy ◽  
...  
Keyword(s):  
Particle Size ◽  
Electrical Resistivity ◽  
Electrical Properties ◽  
Crystallite Size ◽  
Rietveld Analysis ◽  
Tem Analysis ◽  
Lattice Volume ◽  
Edax Analysis ◽  
Cobalt Ferrites ◽  
Structural Variables

Synthesis of Cobalt-Erbium nano-ferrites with formulation CoErxFe2-xO4 (x = 0, 0.005, 0.010, 0.015, 0.020, 0.025, and 0.030) using technique of citrate-gel auto-combustion was done. Characterization of prepared powders was done by using XRD, EDAX, FESEM, AFM and FTIR Spectroscopy, DC resistivity properties respectively. XRD Rietveld Analysis, SEM, TEM and EDAX analysis were taken up in studying spectral, structural, magnetic and electrical properties. XRD pattern of CEF nano particles confirm single phase cubic spinal structure. The structural variables given by lattice constant (a), lattice volume (v), average crystallite size (D) and X-ray density(dx), Bulk density (d), porosity (p), percentage of pore space (P%), surface area (s), strain (ε), dislocation density (δ), along with ionic radii, bond length and hoping length were calculated. SEM and TEM results reveal homogeneous nature of particles accompanied by clusters having no impurity pickup. TEM analysis gives information about particle size of nanocrystalline ferrite while EDAX analysis confirm elemental composition. Emergence of two arch shaped frequency bands (ν1 and ν2) that represent vibrations at tetrahedral site (A) and octahedral site(B) was indicated by spectra of FTIR. The samples electrical resistivity (DC) was measured between 30°C -600°C with Two probe method. XRD Rietveld analysis confirm crystallite size lying between 20.84 nm–14.40 nm while SEM analysis indicate formation of agglomerates and TEM analysis indicate particle size ranging between 24 nm–16 nm. DC Electrical measurements indicate continuous decrease in resistivity with increasing temperature while increasing doping decreases curie temperature. The Magnetic parameters such as Saturation magnetization (Ms), Remanent magnetization (Mr), Coercivity (Hc) and Squareness ratio (R = Mr/Ms), Magnetic moment (nB) were altered by doping of Er+3 content in the increasing order (x = 0.00 to 0.030). The increasing erbium content decreases magnetization thus converting the sample into soft magnetic material. Observations indicated strong dependence of magnetic properties on Erbium substitution and coercivity varies in accordance with anisotropy constant. Due to the presence of magnetic dipole Erbium substituted cobalt ferrites can be used in electromagnetic applications. The present study investigates the effect of different compositions of Er3+ replaced for Fe on structural properties and electrical resistivity of cobalt ferrites.

scholarly journals Temperature Dependence of Initial Permeability of NixCo1-xFe2O4 Ferrite System

2015 ◽  
Vol 16 (4) ◽  
pp. 695-699
Author(s):  
V.S. Bushkova ◽  
A.V. Kopayev ◽  
N.I. Bushkov ◽  
B.V. Karpyk ◽  
O.M. Matkivskyi
Keyword(s):  
Particle Size ◽  
Magnetic Properties ◽  
Surface Layer ◽  
Crystallite Size ◽  
Cobalt Ferrite ◽  
Sol Gel ◽  
Initial Permeability ◽  
Nickel Cobalt ◽  
Auto Combustion ◽  
Ferrite System

The aim of this work was to create and study of ferrite nickel-cobalt powders, using sol-gel technology with participation of auto-combustion. Dependence of the initial permeability from the degree of substitution of cobalt cations on nickel cations is obtained. It is revealed that the crystallite size has a significant influence on the magnetic properties of the samples. With decreasing of crystallite size of nickel-cobalt ferrite Curie temperature decreases. It is shown that the smaller the particle size, the greater the thickness of the surface layer with significant violations of magnetic structure.

Preparation of Magnesium-Based Cobalt-Ferrites (Co1−xMgxFe2O4) Nanoparticles by Sol–Gel Auto Combustion Method

2017 ◽  
Vol 17 (01n02) ◽  
pp. 1760012
Author(s):  
S. Gowreesan ◽  
A. Ruban Kumar
Keyword(s):  
Particle Size ◽  
Structural Parameters ◽  
Sol Gel ◽  
Average Particle Size ◽  
Combustion Method ◽  
Dielectric Behavior ◽  
Powder Xrd ◽  
Average Particle ◽  
Cobalt Ferrites ◽  
Auto Combustion

The scope of the present work is in enhancing the particle size, and dielectric properties of Mg-substituted Cobalt ferrites nanoparticles prepared by sol–gel auto combustion method. The different ratios of Mg-substituted Co Ferrites (Co[Formula: see text]MgxFe2O4([Formula: see text], 0.05, 0.10, 0.15, 0.20 and 0.30)) are calcinated at 850[Formula: see text]C. The synthesized nanoparticles were characterized by powder XRD, FTIR, FE-SEM, EDX techniques and dielectric behavior. The structural parameters were confirmed from powder XRD and the average particle size is obtained from 39 to 67 nm due to the substitution of Mg[Formula: see text] which was calculated by Debye Scherrer’s formula. FE-SEM showed the surface morphology of the different ratio of the sample. The dielectric loss has measured the frequency range of 50[Formula: see text]Hz–5[Formula: see text]MHz. From electrical modulus, conductivity relaxation and thermal activation of charge carriers has been discussed.

scholarly journals Investigation of Structural and Magnetic Properties of Multiferroic La1-Xyxfeo3perovskites, Prepared by Citrate Auto-Combustion Technique

2019 ◽  
Vol 15 ◽  
pp. 6056-6077
Author(s):  
Ahmed Hassan Ibrahim ◽  
Yehia Mohammed Abbas ◽  
Shehab Esmail Mohammed ◽  
Ahmed Bakry Mansour
Keyword(s):  
Magnetic Properties ◽  
Sol Gel ◽  
Particle Diameter ◽  
Average Particle ◽  
Microscopy Imaging ◽  
Transmission Microscopy ◽  
Auto Combustion ◽  
Structural And Magnetic Properties ◽  
Combustion Technique ◽  
Synchrotron Xrd

In this work, we studied the structural and magnetic properties of multiferroic La1-xYxFeO3 perovskites, (x= 0.0, 0.05, 0.1, 0.15, 0.25 and 0.3) which synthesized through Sol-gel auto-combustion technique using a citric acid as a fuel. The room temperature synchrotron X-ray diffraction (XRD) analysis revealed that the all the synthesized samples consisted of the polycrystalline orthorhombic structure perovskites(space group pnma), and tolerance factor confirmed the phase stability of the prepared perovskite system.The Williamson-Hall plot based on synchrotron XRD data were employed to estimate the average particle diameter and varies from 18 nmto 27.8 nm.For a deeper insight of the crystal structure, high resolution transmission microscopy imaging (HRTEM) was performed. The estimated values of crystallite size from HRTEM and synchrotron XRD data were coincident. Many of crystallographic parameters and electron density measurements were calculated by Rietveld refinement of synchrotron XRD data. La1-xYxFeO3 perovskite crystalsarecanted antiferromagnets with a weak ferromagnetism in room temperature.The magnetic properties were gotten through analyzing the magnetization versus temperature M(T) and M(H) hysteresis loop which characterized by a vibrating sample magnetometer (VSM). The molecular structure showed the decrease of the tilting of the octahedra <FeO6> with increasing Y content trying to strengthen the ferromagnetic character. Selected Area Electron Diffraction (SAED) patterns of the investigated samples exhibited spotty ring patterns,confirming the polycrystalline character.The orthoferrite La1-xYxFeO3 crystalsare a promising candidate for optical device applications in broad temperature range and high power system.

The structural and magnetic properties of the nano-CoFe2O4 ferrite prepared by sol-gel auto-combustion technique

2020 ◽  
Vol 817 ◽  
pp. 152786 ◽  
Author(s):  
Mohammed S. Al Maashani ◽  
Kadhim A. Khalaf ◽  
Abbasher M. Gismelseed ◽  
Imaddin A. Al-Omari
Keyword(s):  
Magnetic Properties ◽  
Sol Gel ◽  
Auto Combustion ◽  
Structural And Magnetic Properties ◽  
Combustion Technique

Structural and magnetic properties of Cr doped strontium spinel ferrite SrFe2O4 by sol-gel auto-combustion method

2018 ◽  
Vol 550 ◽  
pp. 90-95 ◽  
Author(s):  
Nazia Yasmin ◽  
Iqra Inam ◽  
Iftikhar Ahmed Malik ◽  
Maria Zahid ◽  
Muhammad Naeem Ashiq ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Spinel Ferrite ◽  
Sol Gel ◽  
Combustion Method ◽  
Auto Combustion ◽  
Structural And Magnetic Properties

Structural and Magnetic Properties of Sm(CobalFe0.1Ni0.12Zr0.04B0.04)7.5 Melt Spun Ribbons

2010 ◽  
Vol 636-637 ◽  
pp. 404-410
Author(s):  
Sofoklis S. Makridis
Keyword(s):  
Magnetic Properties ◽  
Hysteresis Loops ◽  
Secondary Phase ◽  
Maximum Energy ◽  
Tem Analysis ◽  
Energy Product ◽  
Average Grain Size ◽  
Melt Spun ◽  
Melt Spun Ribbons ◽  
Structural And Magnetic Properties

We have investigated the structural and magnetic properties of Sm(Co0.70Fe0.1Ni0.12Zr0.04B0.04)7.5 melt spun ribbons. The arc-melted bulk samples have been used to obtain ribbons at 37 up to 55 m/sec while annealing has been performed in argon atmosphere for 30-75 min at 600-870 oC. In as-spun ribbons the hexagonal SmCo7 (TbCu7-type of structure) of crystal structure has been determined from x-ray diffraction patterns, while fcc-Co has been identified as a secondary phase. After annealing, the 1:7 phase of the as-spun ribbons transforms into 2:17 and 1:5 phases. TEM analysis shows a homogeneous nanocrystalline microstructure with average grain size of 30-80 nm. Coercivity values of 15-27 kOe are obtained from hysteresis loops traced at non-saturating fields. The coercivity decreases as temperature increases, but it is high enough to maintain values higher than 5 kOe at 380 oC. The maximum energy product at room temperature increases, as high as 7.2 MGOe, for melt-spun ribbons produced at higher wheel speed.

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