Ferromagnetic Resonance in Cobalt Ferrite at High Temperature

1951 ◽  
Vol 84 (2) ◽  
pp. 372-372 ◽  
Author(s):  
Tosihiko Okamura ◽  
Yosiharu Torizuka ◽  
Yuzo Kojima
Keyword(s):  
High Temperature ◽  
Ferromagnetic Resonance ◽  
Cobalt Ferrite

High Temperature Conductivity Study of Cobalt Ferrite

2014 ◽  
Vol 20 (3) ◽  
pp. 683-685
Author(s):  
R. K. Panda ◽  
D. Behera
Keyword(s):  
High Temperature ◽  
Cobalt Ferrite ◽  
Temperature Conductivity

Significance of Cobalt Ferrite Nanoparticles on Superconducting Properties of Tl-1212 High Temperature Superconductor

2021 ◽  
Vol 31 ◽  
pp. 1-5
Author(s):  
Nurul Auni Khalid ◽  
Wei Kong ◽  
Ing Kong ◽  
Cin Kong ◽  
Mohd Mustafa Awang Kechik ◽  
...  
Keyword(s):  
High Temperature ◽  
High Temperature Superconductor ◽  
Cobalt Ferrite ◽  
Compositional Analysis ◽  
Diffraction Method ◽  
Solid State Reaction Method ◽  
Ferrite Nanoparticles ◽  
X Ray ◽  
Cobalt Ferrite Nanoparticles ◽  
Oxide Powders

Thallium-based high temperature superconductor (HTS) with nominal starting composition (Tl0.85Cr0.15)Sr2CaCu2O7-δ (Tl-1212) was prepared using high purity oxide powders via solid state reaction method. Small amounts (0.0 – 0.15 wt. %) of cobalt ferrite nanoparticles (CoFe2O4) were added into Tl-1212 superconductors. The effect of CoFe2O4 nanoparticles addition on the critical temperature (Tc), phase formation and microstructure properties including elemental compositional analysis were studied. The samples were investigated by the characterization of electrical resistance measurement, powder X-ray diffraction method (XRD), scanning electron microscopy and energy dispersive X-ray analysis (EDX). Zero-resistance temperature (Tc-zero) was found to reduce from 97 K to 89 K with increasing of CoFe2O4 nanoparticles concentration. Most of the samples indicated a dominant Tl-1212 phase of a tetragonal structure with a minor phase of Tl-1201. SEM micrographs with EDX mapping showed that CoFe2O4 nanoparticles were well distributed in all the samples.

scholarly journals Mechanothermal Solid-state Synthesis of Cobalt(II) Ferrite and Determination of its Heat Capacity by MTDSC

2010 ◽  
Vol 65 (12) ◽  
pp. 1434-1438 ◽  
Author(s):  
Vittorio Berbenni ◽  
Chiara Milanese ◽  
Giovanna Bruni ◽  
Alessandro Girella ◽  
Amedeo Marini
Keyword(s):  
Heat Capacity ◽  
High Temperature ◽  
Solid State ◽  
Thermal Activation ◽  
Molar Heat Capacity ◽  
Cobalt Ferrite ◽  
High Energy ◽  
Stoichiometric Mixture ◽  
X Ray

Cobalt ferrite (CoFe2O4) has been synthesized by a solid-state mechanothermal process, and its molar heat capacity has been determined. A stoichiometric mixture of CoC2O4 ・ 2H2O and FeC2O4 ・ 2H2O was subjected to a combination of mechanical activation (by high-energy milling) and thermal activation (by annealing at temperatures between 300 and 700 °C). The process was followed by thermogravimetric analysis and high-temperature X-ray powder diffraction. It has been shown that CoFe2O4 forms at all temperatures, though with different degrees of crystallization, while Co3O4 and Fe2O3 are the only products formed when starting from unmilled mixtures. The molar heat capacity of CoFe2O4 has been determined in the temperature range 60 - 400 °C by MTDSC. It has been shown that the molar CP values of CoFe2O4 samples produced at T ≥ 500 °C are close to each other while those of the samples produced at 300 and 400 °C are lower. Furthermore the CoFe2O4 samples prepared at T ≥ 500 °C show very similar microstructures.

scholarly journals Flash Light Sintered Lanthanum Strontium Cobalt Ferrite(LSCF) Electrode for High Performance IT-SOFCs

Ceramist ◽  
2021 ◽  
Vol 24 (4) ◽  
pp. 399-410
Author(s):  
Junghum Park ◽  
Hojae Lee ◽  
Yonghyun Lim ◽  
Jisung Yoon ◽  
Miju Ku ◽  
...  
Keyword(s):  
High Temperature ◽  
Cobalt Ferrite ◽  
Energy Dispersive Spectrometer ◽  
Secondary Phase ◽  
Solid Oxide ◽  
Oxide Material ◽  
Sintering Process ◽  
Fuel Cell Performance ◽  
Lanthanum Strontium ◽  
Thermal Sintering

The high temperature(900oC~) thermal sintering process is necessary to fabricate the Solid oxide fuel cells(SOFCs). However, the chemical reaction has occurred between solid oxide material components, electrode and electrolyte. In the case of lanthanum strontium cobalt ferrite (La0.6Sr0.4Co0.2Fe0.8O3-δ, LSCF) electrode, the SrZrO3(SZO) secondary phase is produced at the electrolyte interface even when using the gadolinium doped ceria(GDC) buffer layer for blocking the strontium and zirconium diffusion. The SZO layer hinders the oxygen ion transfer and deteriorates fuel cell performance. By using a novel flash light sintering(FLS) method, we have successfully solved the problem of secondary phase formation in the conventional high temperature thermal sintering process. The microstructure and thickness of the LSCF electrode are analyzed using a field emission scanning electron microscope(FE-SEM). The strontium diffusion and secondary phase are confirmed by X-ray diffraction (XRD), energy dispersive spectrometer method of SEM, TEM (SEM-, TEM-EDS). The NiO-YSZ anode supported LSCF cathode cells are adopted for electro chemical analysis which is measured at 750oC. The maximum power density of the thermal sintered LSCF cathode at 1050oC is 699.6mW/cm2, while that of the flash light sintered LSCF cathode is 711.6mW/cm2. This result proves that the electrode was successfully sintered without a secondary phase using flash light sintering.

High-Temperature Magnetic Behaviour of 10 % Aluminium-Substituted Cobalt Ferrite

2017 ◽  
Vol 30 (6) ◽  
pp. 1629-1634 ◽  
Author(s):  
Lawrence Kumar ◽  
Pawan Kumar ◽  
Mukesh Kumar Zope ◽  
Manoranjan Kar
Keyword(s):  
High Temperature ◽  
Cobalt Ferrite ◽  
Magnetic Behaviour

High temperature ferromagnetic resonance study on pMTJ stacks with diffusion barrier layers

2018 ◽  
Vol 51 (40) ◽  
pp. 405001 ◽  
Author(s):  
W C Law ◽  
T Tahmasebi ◽  
F N Tan ◽  
T L Jin ◽  
W L Gan ◽  
...  
Keyword(s):  
High Temperature ◽  
Ferromagnetic Resonance ◽  
Diffusion Barrier ◽  
Barrier Layers
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