Low-temperature oxidation of Mn3O4 hausmannite

被引：70
作者：
Fritsch, S
Sarrias, J
Rousset, A
Kulkarni, GU [1 ]
机构：
[1] Jawaharlal Nehru Ctr Adv Sci Res, Chem & Phys Mat Unit, Bangalore 560064, Karnataka, India
[2] Univ Toulouse 3, Lab Chim Mat Inorgan, ESA 5070, F-31062 Toulouse, France
来源：
MATERIALS RESEARCH BULLETIN | 1998年 / 33卷 / 08期
关键词：
oxides; thermogravimetric analysis (TGA); XAFS; (EXAFS; XANES); X-ray diffraction;
D O I：
10.1016/S0025-5408(98)00108-1
中图分类号：
T [工业技术];
学科分类号：
08 ;
摘要：
Hausmannite, Mn3O4, with a specific surface area of 10 m(2)/g has been oxidized at low temperatures (300 degrees C < T < 425 degrees C). In this temperature range both Mn2+ and Mn3+ cations are oxidized. The oxidation of Mn2+ to Mn3+ is governed by a diffusion process and the spinel structure is stable up to 425 degrees C. Oxidation of Mn3+ to Mn4+ leads to the crystallization of the Mn5O8 phase. Careful oxidation studies show the formation of two metastable manganese oxides, Mn5O8 and a defect spinel of the formula Mn2O2.78. The coordination numbers and the cation-anion distances in Mn3O4, gamma-Mn2O2.78 and alpha-Mn2O3 obtained by EXAFS (extended X-ray absorption fine structure) are compared. (C) 1998 Elsevier Science Ltd.
引用
收藏
页码：1185 / 1194
页数：10
相关论文
共 26 条
  • [1] BRANER G, 1963, HDB PREPARATIVE INOR, V1, P2
  • [2] BRICKER O, 1965, AM MINERAL, V50, P1296
  • [3] COLLONGUES R, 1971, NANSTOICHIOMETRIE
  • [4] DOLLIMORE D, 1971, P 3 ICTA Z, P91
  • [5] Dubois P, 1936, ANN CHIM FRANCE, V5, P411
  • [6] FEITKNECHT W, 1945, HELV CHIM ACTA, V28, P148
  • [7] FRITSCH S, 1995, THESIS TOULOUSE
  • [8] OXIDATION MECHANISM OF MANGANESE-SUBSTITUTED MAGNETITE
    GILLOT, B
    ELGUENDOUZI, M
    TAILHADES, P
    ROUSSET, A
    [J]. REACTIVITY OF SOLIDS, 1986, 1 (02): : 139 - 152
  • [9] PHASE TRANSFORMATION-RELATED KINETIC IN THE OXIDATION OF A MANGANESE MIXED-OXIDE WITH A SPINEL STRUCTURE
    GILLOT, B
    ELGUENDOUZI, M
    KHARROUBI, M
    TAILHADES, P
    METZ, R
    ROUSSET, A
    [J]. MATERIALS CHEMISTRY AND PHYSICS, 1989, 24 (1-2) : 199 - 208
  • [10] STUDY BY THERMOGRAVIMETRY, ELECTRICAL-CONDUCTIVITY AND IR SPECTROMETRY OF THE PHASE-TRANSITION FOR MANGANESE CATION DEFICIENT SPINELS
    GILLOT, B
    ELGUENDOUZI, M
    LAARJ, M
    TAILHADES, P
    ROUSSET, A
    [J]. JOURNAL OF MATERIALS SCIENCE, 1988, 23 (09) : 3342 - 3347
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