Fine-grained spinel ferrites: From the reactivity to magnetic properties

被引:21
作者
Gillot, B [1 ]
机构
[1] Univ Bourgogne, Lab Rech React Solides, F-21011 Dijon, France
关键词
D O I
10.1051/epjap:1998267
中图分类号
O59 [应用物理学];
学科分类号
摘要
The oxidation at low temperature of fine-grained ferrites containing oxidizable cations such as Cu+, Fe2+, Mn2+, Mo3+, V3+, has led to new mixed-valent cation deficient ferrites with a large number of vacancies. It has been demonstrated by DTG analysis that each cation oxidizes at a specific temperature in close relation with the cation-oxygen distance. The kinetics oxidation of each oxidizable cation has been explained on the basis of a diffusion-induced stress effect when these stresses are generated by the chemical gradient induced during the oxidation process. When fine-grained ferrites contain some Co-cations, it has been revealed that the stresses have a significant influence on the enhancement of the coercivity.
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页码:243 / 250
页数:8
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