EFFECT OF A PRETREATMENT UNDER HIGH-PRESSURE ON THE OXIDATION MECHANISM OF MAGNETITE TO GAMMA-FE2O3 AND ON THE TRANSFORMATION GAMMA-FE2O3 TO ALPHA-FE2O3

被引:11
|
作者
GILLOT, B [1 ]
NOUAIM, H [1 ]
MATHIEU, F [1 ]
ROUSSET, A [1 ]
机构
[1] UNIV TOULOUSE 3,CHIM MAT INORGAN LAB,CNRS,URA 1311,F-31062 TOULOUSE,FRANCE
关键词
D O I
10.1016/0254-0584(91)90074-5
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
Kinetic analysis of the thermogravimetric curves obtained for the oxidation in gamma-Fe2O3 of a single block of Fe3O4 prepared under high pressure (5.5 GPa) revealed a diffusion mechanism in which the diffusion is not isotropic but limited along the crystallographic direction. It is also found that for gamma-Fe2O3 derived from a single block of Fe3O4, the vacancies do not form an ordered structure while the temperature of the gamma-Fe2O3 to alpha-Fe2O3 transformation decreases from about 390-degrees-C for gamma-Fe2O3 obtained from Fe3O4 powder to 300-degrees-C for gamma-Fe2O3 derived from a Fe3O4 block.
引用
收藏
页码:389 / 397
页数:9
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