Influence of reduction temperature on coercivities, coercivity factors and rheological properties of γ-Fe2O3and silica coated γ-Fe2O3
- 1 May 1979
- journal article
- Published by Institute of Electrical and Electronics Engineers (IEEE) in IEEE Transactions on Magnetics
- Vol. 15 (3) , 1068-1072
- https://doi.org/10.1109/tmag.1979.1070327
Abstract
The transformation of &-FeOOH into &-Fe2O3via Fe3O4is studied in order to determine the influence of the reduction temperature on the magnetic and rheological properties of the final product. The study was carried out both on pure and on silica coated &-FeOOH. It was found that the reduction temperature at which a maximum of coercivity is obtained, varies with particle size, and it is much higher for silica coated samples which also show higher coercivity at the optimum reduction temperature. Coercivity factors (CF percent) and Mr/Ms values are also dependent on particle size. It is shown that coating with silica enables the reduction to be carried out at higher temperatures without significant collapse of the acicular shape.Keywords
This publication has 4 references indexed in Scilit:
- Magnetic and microstructural properties of SiO2-modified γ-Fe2O3 prepared in a fluid bed furnaceCeramurgia International, 1976
- Mechanisms of iron oxides reduction at temperatures below 400°CMaterials Science and Engineering, 1967
- Remanent magnetization of fine particlesJournal de Physique et le Radium, 1959
- Relations between Different Modes of Acquisition of the Remanent Magnetization of Ferromagnetic ParticlesJournal of Applied Physics, 1958