Raman and magnetization studies of barium ferrite powder prepared by water-in-oil microemulsion

2000 ◽  
Vol 15 (2) ◽  
pp. 483-487 ◽  
Author(s):  
M. S. Chen ◽  
Z. X. Shen ◽  
X. Y. Liu ◽  
J. Wang
Keyword(s):  
Magnetic Properties ◽  
Calcination Temperature ◽  
Raman Spectra ◽  
Ferrite Powder ◽  
X Ray Diffraction ◽  
Ferric Ions ◽  
Frequency Shifts ◽  
X Ray ◽  
Calcination Temperatures ◽  
Crystallization Effect

Micro-Raman spectroscopy was used to study the formation of BaFe12O19 (BaM) powders derived from water-in-oil microemulsion at different calcination temperatures. With increase in the calcination temperature, the Raman spectra of the BaM powders become narrower and stronger without apparent frequency shifts of the Raman bands. The calcination temperature dependence of the Raman spectra and the magnetic properties of the BaM powders result from the crystallization rather than size effect. Our results show that there is a strong correlation between the crystallinity and the magnetic properties, which could be explained in terms of the crystallization effect on the superexchange interaction between ferric ions. The γ–Fe2O3 phase occurred in the BaM precursor and the powder calcined at 500 °C. The α–Fe2O3 phase was developed in the powders calcined at 500, 600, and 700 °C, which was not detected by x-ray diffraction. With increasing calcination temperature, the γ–Fe2O3 phase can either react with oxide containing barium to form the BaM phase or transform to the α–Fe2O3 phase. The amount of α–Fe2O3 decreases due to reaction with BaCO3 to form BaM phase at higher calcination temperature.

Structural and Magnetic Properties of Ni0.5Zn0.5Fe2O4 Synthesized through the Sol-Gel Method

2014 ◽  
Vol 664 ◽  
pp. 75-79
Author(s):  
Beh Hoe Guan ◽  
Muhammad Hanif Zahari ◽  
Lee Kean Chuan
Keyword(s):  
Magnetic Properties ◽  
Calcination Temperature ◽  
Sol Gel ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Calcination Temperatures ◽  
Zn Ferrite

This study investigates the influence of calcination temperatures on the magnetic properties of Ni0.5Zn0.5Fe2O4(Ni-Zn) ferrites.Ni-Zn ferrite with the chemical formula Ni0.5Zn0.5Fe2O4was prepared from their respective nitrate salts through the sol-gel method. The resulting ferrites were characterized using X-ray diffraction (XRD), field emission scanning electron microscope (FESEM) and vibrating sample magnetometer (VSM). Single phased Ni0.5Zn0.5Fe2O4 was obtained at all calcination temperatures.FESEM Micrographs reveals an increase in the grain size with the increase of the calcination temperature. Consequently, the magnetic saturation of the samples were found to increase with each increase in the calcination temperature where the highest value obtained is 70.58 emu/g for the samples calcined at 1000°C.

The Effect of Calcination Temperature on Electrochemical Performance of Porous LaMnO3 Catalyst in Al-Air Battery

2017 ◽  
Vol 727 ◽  
pp. 657-662 ◽  
Author(s):  
Fu Wei Xiang ◽  
Xiu Hua Chen ◽  
Hui Wen Ma ◽  
Jie Yu ◽  
Hui Zhang ◽  
...  
Keyword(s):  
Calcination Temperature ◽  
Discharge Voltage ◽  
Cell Polarization ◽  
X Ray Diffraction ◽  
Half Cell ◽  
X Ray ◽  
Calcination Temperatures ◽  
Cell Discharge ◽  
Air Battery ◽  
Discharge Test

This study focuses on the development of the pervoskite catalyst for aluminum-air battery. The catalyst powders of porous pervoskite LaMnO3 were prepared by template method with different calcination temperatures. Material characteristics of prepared samples were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and thermalgravimetry (TG). The half-cell polarization curves and cyclic voltammetry curves were found to be strongly depended on the calcination temperature. The result showed the optimized calcination temperature was 650°C. The full-cell discharge test in NaCl solution (3.5 wt%) with a constant discharge current of 10 mA/cm2 was performed at room temperature, and the discharge voltage of sample synthesized under optimized calcination temperature was 0.73 V.

scholarly journals Effect of Calcination Temperature on the Synthesis of ZrO2-Pillared Saponite to Catalytic Activity in Menthol Esterification

2018 ◽  
Vol 16 (1) ◽  
pp. 8 ◽  
Author(s):  
Is Fatimah ◽  
Dwiarso Rubiyanto ◽  
Nanda Candra Kartika
Keyword(s):  
Catalytic Activity ◽  
Surface Area ◽  
Calcination Temperature ◽  
Surface Acidity ◽  
Physicochemical Characteristics ◽  
Sem Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Calcination Temperatures ◽  
Solid Acidity

The influence of calcination temperature on the synthesis of zirconia-pillared saponite (PILS) and on its catalytic activity in menthol esterification has been studied. Zirconia pillarization was conducted using zirconium tetraisopropoxide as a precursor and with calcination temperatures of 450, 600 and 700 °C. Evaluation of physicochemical characteristics at these varied temperatures was carried out by X-Ray Diffraction (XRD), surface area analysis, Scanning Electron Eicroscope (SEM) analysis, Differential Thermal Analysis (DTA) and total acidity. The obtained results indicate that the structure and surface acidity of saponite were strongly influenced by calcination temperature. The solid acidity and surface parameters such as specific surface area, pore volume, and pore radius play an important role in the total conversion and selectivity in menthol esterification.

The crystal structure of RbCdCl3 and the polarized Raman spectra of RbCdX3 (X = Cl, Br)

1978 ◽  
Vol 56 (9) ◽  
pp. 1192-1195 ◽  
Author(s):  
Mahadevan Natarajan ◽  
Helen Elaine Howard-Lock ◽  
Ian David Brown
Keyword(s):  
Crystal Structure ◽  
Single Crystals ◽  
Raman Spectra ◽  
X Ray Diffraction ◽  
Frequency Shifts ◽  
X Ray ◽  
Polarized Raman

The polarized Raman spectra of single crystals of RbCdCI3 and RbCdBr3 (isostructural with NH4CdCl3) have been measured and analysed by comparison of the frequency shifts. The crystal structure of RbCdCl3 refined by X-ray diffraction is also reported.

Sr1-xNdXFe12O19 Ferrite Synthesized through Sol-Gel Self-Combustion

2010 ◽  
Vol 146-147 ◽  
pp. 147-150 ◽  
Author(s):  
Zhan Yong Wang ◽  
Ming Lin Jin ◽  
Hui Chun Qian ◽  
Yong Zheng Fang ◽  
Jia Yue Xu
Keyword(s):  
Magnetic Properties ◽  
Citric Acid ◽  
Calcination Temperature ◽  
Differential Scanning Calorimeter ◽  
Sol Gel ◽  
Vibrating Sample Magnetometer ◽  
Doping Content ◽  
X Ray Diffraction ◽  
X Ray

Sr1-xNdxFe12O19 ferrites were Synthesized via sol–gel and self-combustion methods with Fe(NO3)3·9H2O，Sr(NO3)2 and citric acid. The as-synthesized powder was studied by differential scanning calorimeter (DSC). X-ray diffraction (XRD) and vibrating sample magnetometer (VSM) were applied to investigate the structure and magnetic properties. The powder was synthesized in different calcination temperature and doping content of Nd2O3. The experiment reveals that the magnetic properties of Nd3+ doped ferrites are less sensitive to calcination temperature comparing with no doping ferrites. The coercivity (Hcj) of Nd3+ doped ferrites reach 423.96 kA·m-1.

Study the Effect of the Substitution of Ba with Pr in Barium Ferrite Powder on Magnetic Properties

2014 ◽  
Vol 1025-1026 ◽  
pp. 440-444
Author(s):  
Pornpen Marawichayo ◽  
Wirunya Keawwattana ◽  
Nattamon Koonsaeng ◽  
Pongsakorn Jantaratana
Keyword(s):  
Magnetic Properties ◽  
Coercive Field ◽  
Barium Ferrite ◽  
Barium Hexaferrite ◽  
Ferrite Powder ◽  
X Ray Diffraction ◽  
One Pot ◽  
X Ray ◽  
Saturation Magnetisation ◽  
Substituted Barium Hexaferrite

Pr substituted barium hexaferrite, Ba1-xPrxFe12O19 with x = 0.00-0.20 were synthesized by Oxide One Pot Synthesis (OOPS) process. The phase composition of Ba1-xPrxFe12O19 were characterized by X-ray diffraction analysis (XRD). The phase morphology of the barium hexaferrite powder was studied by scanning electron microscope (SEM) and energy dispersive X-ray (EDX) spectroscopy confirmed that the Pr completely substituted into barium ferrite. The magnetic properties was investigated by vibrating sample magnetometry (VSM). It was found that saturation magnetisation and coercive field can be improved by the substitution of Ba with Pr in BaFe12O19 powder. The saturation magnetisation increased at first to the maximum of 50 emu g-1 (x = 0.15) and then decreased to the 34 emu g-1 (x = 0.20), while the coercive field increased remarkably with increasing Pr ions content.

scholarly journals Effect of Co Substitution and Thermo-Magnetic Treatment on the Structure and Induced Magnetic Anisotropy of Fe84.5−xCoxNb5B8.5P2 Nanocrystalline Alloys

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3433
Author(s):  
Aleksandra Kolano-Burian ◽  
Przemyslaw Zackiewicz ◽  
Agnieszka Grabias ◽  
Anna Wojcik ◽  
Wojciech Maziarz ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Properties ◽  
Melt Spinning ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Transmission Electron ◽  
Induced Magnetic Anisotropy ◽  
Crystallization Effect ◽  
Magnetic Techniques

In the present work, we investigated in detail the thermal/crystallization behavior and magnetic properties of materials with Fe84.5-xCoxNb5B8.5P2 (x = 0, 5, 10, 15 and 20 at.%) composition. The amorphous ribbons were manufactured on a semi-industrial scale by the melt-spinning technique. The subsequent nanocrystallization processes were carried out under different conditions (with/without magnetic field). The comprehensive studies have been carried out using differential scanning calorimetry, X-ray diffractometry, transmission electron microscopy, hysteresis loop analyses, vibrating sample magnetometry and Mössbauer spectroscopy. Moreover, the frequency (up to 300 kHz) dependence of power losses and permeability at a magnetic induction up to 0.9 T was investigated. On the basis of some of the results obtained, we calculated the values of the activation energies and the induced magnetic anisotropies. The X-ray diffraction results confirm the surface crystallization effect previously observed for phosphorous-containing alloys. The in situ microscopic observations of crystallization describe this process in detail in accordance with the calorimetry results. Furthermore, the effect of Co content on the phase composition and the influence of annealing in an external magnetic field on magnetic properties, including the orientation of the magnetic spins, have been studied using various magnetic techniques. Finally, nanocrystalline Fe64.5Co20Nb5B8.5P2 cores were prepared after transverse thermo-magnetic heat treatment and installed in industrially available portable heating equipment.

scholarly journals Effect of calcination temperature on the structural, optical and magnetic properties of pure and Fe-doped ZnO nanoparticles

2016 ◽  
Vol 34 (2) ◽  
pp. 451-459 ◽  
Author(s):  
Raminder Preet Pal Singh ◽  
I.S. Hudiara ◽  
Shashi Bhushan Rana
Keyword(s):  
Magnetic Properties ◽  
Calcination Temperature ◽  
Zno Nanoparticles ◽  
Average Crystallite Size ◽  
Hexagonal Wurtzite Structure ◽  
Ferric Nitrate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Magnetization Saturation ◽  
Doped Zno

AbstractIn the present study, pure ZnO and Fe-doped ZnO (Zn0.97Fe0.03O) nanoparticles were synthesized by simple coprecipitation method with zinc acetate, ferric nitrate and sodium hydroxide precursors. Pure ZnO and Fe-doped ZnO were further calcined at 450 °C, 600 °C and 750 °C for 2 h. The structural, morphological and optical properties of the samples were characterized by X-ray diffractometer (XRD), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and UV-Vis absorption spectroscopy. The X-ray diffraction studies revealed that the as-synthesized pure and doped ZnO nanoparticles have hexagonal wurtzite structure. The average crystallite size was calculated using Debye-Scherrer’s formula. The particle size was found to be in nano range and increased with an increase in calcination temperature. SEM micrographs confirmed the formation of spherical nanoparticles. Elemental compositions of various elements in pure and doped ZnO nanoparticles were determined by EDX spectroscopy. UV-Vis absorption spectra showed red shift (decrease in band gap) with increasing calcination temperature. Effect of calcination on the magnetic properties of Fe-doped ZnO sample was also studied using vibrating sample magnetometer (VSM). M-H curves at room temperature revealed that coercivity and remanent polarization increase with an increase in calcination temperature from 450 °C to 750 °C, whereas reverse effect was observed for magnetization saturation.

scholarly journals Green synthesis and characterization of hexaferrite strontium-perovskite strontium photocatalyst nanocomposites

2020 ◽  
Vol 43 (1) ◽  
pp. 26-42 ◽  
Author(s):  
Zahra Hajian Karahroudi ◽  
Kambiz Hedayati ◽  
Mojtaba Goodarzi
Keyword(s):  
Magnetic Properties ◽  
Green Synthesis ◽  
Sol Gel ◽  
Synthesis Method ◽  
Combustion Method ◽  
Lemon Juice ◽  
X Ray Diffraction ◽  
X Ray ◽  
Auto Combustion

AbstractThis study presents a preparation of SrFe12O19– SrTiO3 nanocomposite synthesis via the green auto-combustion method. At first, SrFe12O19 nanoparticles were synthesized as a core and then, SrTiO3 nanoparticles were prepared as a shell for it to manufacture SrFe12O19–SrTiO3 nanocomposite. A novel sol-gel auto-combustion green synthesis method has been used with lemon juice as a capping agent. The prepared SrFe12O19–SrTiO3 nanocomposites were characterized by using several techniques to characterize their structural, morphological and magnetic properties. The crystal structures of the nanocomposite were investigated via X-ray diffraction (XRD). The morphology of SrFe12O19– SrTiO3 nanocomposite was studied by using a scanning electron microscope (SEM). The elemental composition of the materials was analyzed by an energy-dispersive X-ray (EDX). Magnetic properties and hysteresis loop of nanopowder were characterized via vibrating sample magnetometer (VSM) in the room temperature. Fourier transform infrared spectroscopy (FTIR) spectra of the samples showed the molecular bands of nanoparticles. Also, the photocatalytic behavior of nanocomposites has been checked by the degradation of azo dyes under irradiation of ultraviolet light.

scholarly journals Influence of Li2CO3 addition on electrical and magnetic properties of Ni0.6Mg0.4Fe2O4

2020 ◽  
Vol 10 (03) ◽  
pp. 2050003
Author(s):  
M. R. Hassan ◽  
M. T. Islam ◽  
M. N. I. Khan
Keyword(s):  
Magnetic Properties ◽  
Single Phase ◽  
Low Frequency ◽  
Solid State Reaction Method ◽  
Charge Carriers ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electrical And Magnetic Properties ◽  
Frequency Regime ◽  
Xrd Patterns

In this research, influence of adding Li2CO3 (at 0%, 2%, 4%, 6%) on electrical and magnetic properties of [Formula: see text][Formula: see text]Fe2O4 (with 60% Ni and 40% Mg) ferrite has been studied. The samples are prepared by solid state reaction method and sintered at 1300∘C for 6[Formula: see text]h. X-ray diffraction (XRD) patterns show the samples belong to single-phase cubic structure without any impurity phase. The magnetic properties (saturation magnetization and coercivity) of the samples have been investigated by VSM and found that the higher concentration of Li2CO3 reduces the hysteresis loss. DC resistivity increases with Li2CO3 contents whereas it decreases initially and then becomes constant at lower value with temperature which indicates that the studied samples are semiconductor. The dielectric dispersion occurs at a low-frequency regime and the loss peaks are formed in a higher frequency regime, which are due to the presence of resonance between applied frequency and hopping frequency of charge carriers. Notably, the loss peaks are shifted to the lower frequency with Li2CO3 additions.

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