When highly divided spinel fenites become reactive enough with oxygen, to allow the oxidation of the Fe ions at low temperature and of substitute cations too, when these cations are capable of different valence states. We prepared fine particles of spinel ferrites substituted by Mn, Mo, Cu, by "chimie douce", especially from oxalate precursors and used them to reveal and to study the oxido-redu...

The optical properties of multi-functionalized cobalt ferrite (CoFe2O4), cobalt zinc ferrite (Co0.5Zn0.5Fe2O4), and zinc ferrite (ZnFe2O4) nanoparticles have been enhanced by coating them with silica shell using a modified Stöber method. The ferrites nanoparticles were prepared by a modified citrate gel technique. These core/shell ferrites nanoparticles have been fired at temperatures: 400°C, 6...

Ferrites with spinel structure are the most widespread materials in radio engineering, electronics and communication industry, microwave devices and computer facilities. The change of synthesis temperature of ferrites results in cation redistribution of iron, which updates crystal properties, as macroscopic magnetic properties of ferrites. Among this extensive class of compounds nickel and copp...

We have studied the integration of Ni-Cu-Zn ferrite spinels as well as substituted hexagonal Co2Y-and M-type ferrites into LTCC (Low Temperature Ceramic Co-firing) modules. The cofiring behavior and the magnetic properties of these materials were investigated and evaluated for multilayer applications. Ni-Cu-Zn ferrites exhibit permeabilities of μ = 300 – 500 for operating frequencies in the MHz...

Calculations for the magnetic dipolar contribution to the magnetic anisotropy of BaFeizOie and LaFeiiZnOie M-type and BaFerMn2Oil A-type hexagonal ferrites have been made. Our calculations take into account all the magnetic moments existing within a sphere with a radius of 118 1, from which good eonvergenee is reached. The results for there ferrite# suggest that the strong magnetic enisotropy i...

Numerous applications of hexagonal ferrites are related to their easy axis or easy plane magnetocrystalline anisotropy configurations. Certain W-type ferrites undergo spin reorientation transitions (SRT) between different anisotropy states on magnetic field or temperature variation. The transition point can be tuned by modifying the chemical composition, which suggests a potential application o...

The temperature dependence of core loss in cobalt substituted Ni-Zn-Cu ferrites was investigated. Co ions are known to lead to a compensation of the magnetocrystalline anisotropy in Ni-Zn ferrites, at a temperature depending on the cobalt content and the Ni / Zn ratio. We observed similar behaviour in Ni-Zn-Cu and it was found that the core loss goes through a minimum around this magneto-crysta...

Magnetic oxides are naturally occurring minerals. In order to understand their unique properties and their utilization in technological applications, one must fully understand the correlation between chemistry, structure, particle size and processing. Among the broad classification of magnetic oxides, the spinel ferrites gain much importance because of their low cost, high magnetic permeability...

the mössbauer spectra of nanoferrite materials such as ni0.25mn0.75fe2o4, co0.5mn0.5fe2o4 and ni0.4co0.6fe2o4 have been reported and the above materials were prepared by sol-gel combustion method using metal nitrates as source material and polyvinyl alcohol(pva) as agglomeration reducing agent. as the structural, thermal and magnetic properties (vsm) of the above ferrites have been published al...

Some spinel ferrites, MFe2O4 (M = Cu, Cd and Zn), having submicron grain sizes (0.1–0.7μm) were prepared by sol-gel-selfcombustion and their sensing properties to reducing gases were investigated. The gas sensing characteristics were obtained by measuring the sensitivity as a function of various controlling factors, like operating temperature, composition and concentration of the gas, and final...