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

来源：

MATERIALS CHEMISTRY AND PHYSICS | 1991年 / 28卷 / 04期

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

页码：389 / 397

页数：9

共 22 条

[1]

Barret P., 1973, CINETIQUE HETEROGENE

[2] MECHANISM OF LOW TEMPERATURE OXIDATION OF MAGNETITES [J].

COLOMBO, U ;

FAGHERAZZI, G ;

GAZZARRI.F ;

LANZAVECCHIA, G ;

SIRONI, G .

NATURE, 1968, 219 (5158) :1036-+

[3]

DECHAMBRE G, 1983, B SOC CHIM FR, V1, P229

[4] UBER DIE OXYDATION VON FE3O4 ZU GAMMA- UND ALPHA-FE2O3 - DIE DIFFERENZTHERMOANALYTISCHE (DTA) UND THERMOGRAVIMETRISCHE (TG) VERFOLGUNG DES REAKTIONSABLAUFES AN KUNSTLICHEN FORMEN VON FE3O4 [J].

EGGER, K ;

FEITKNECHT, W .

HELVETICA CHIMICA ACTA, 1962, 45 (06) :2042-&

[5] UBER DIE OXYDATION VON MAGNETIT ZU GAMMA-FE2O3 - VORLAUFIGE MITTEILUNG [J].

FEITKNECHT, W ;

LEHMANN, HW .

HELVETICA CHIMICA ACTA, 1959, 42 (06) :2035-2039

[6] MECHANISM OF OXIDATION OF MAGNETITE TO GAMMA-FE2O3 [J].

GALLAGHE.KJ ;

FEITKNEC.W ;

MANNWEIL.U .

NATURE, 1968, 217 (5134) :1118-&

[7] CORRELATION BETWEEN THE VARIATION OF THE DIFFUSION-COEFFICIENT OF THE VACANCIES AND THEIR CONCENTRATION IN THE PARTIALLY OXIDIZED SPINELS IN DEFECT PHASE-GAMMA [J].

GILLOT, B ;

BARRET, P .

SOLID STATE IONICS, 1984, 12 (MAR) :443-448

[8]

GILLOT B, 1978, ANN CHIM FRANCE, V3, P209

[9] ROLE OF CRYSTALLITE SIZE IN THE OXIDATION OF FERROUS SPINELS [J].

GILLOT, B ;

CHASSAGNEUX, F ;

ROUSSET, A .

MATERIALS CHEMISTRY, 1981, 6 (4-5) :233-253

[10] INFLUENCE OF CRYSTALLITE SIZE ON OXIDATION-KINETICS OF MAGNETITE [J].

GILLOT, B ;

ROUSSET, A ;

DUPRE, G .

JOURNAL OF SOLID STATE CHEMISTRY, 1978, 25 (03) :263-271

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