FE-CR/AL2O3 METAL-CERAMIC COMPOSITES - NATURE AND SIZE OF THE METAL PARTICLES FORMED DURING HYDROGEN REDUCTION

被引:30
作者
LAURENT, C
DEMAI, JJ
ROUSSET, A
KANNAN, KR
RAO, CNR
机构
[1] INDIAN INST SCI,SOLID STATE & STRUCT CHEM UNIT,BANGALORE 560012,KARNATAKA,INDIA
[2] UNIV PAUL SABATIER,CHIM MAT INORGAN LAB,CNRS,URA 1311,F-31062 TOULOUSE,FRANCE
关键词
D O I
10.1557/JMR.1994.0229
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
Fe-Cr/Al2O3 metal-ceramic composites prepared by hydrogen reduction at different temperatures and for different periods have been investigated by a combined use of Mossbauer spectroscopy, x-ray diffraction, transmission electron microscopy, and energy-dispersive x-ray spectroscopy in order to obtain information on the nature of the metallic species formed. Total reduction of Fe3+ does not occur by increasing the reduction time at 1320 K from 1 to 30 h, and the amount of superparamagnetic metallic species is essentially constant (about 10%). Temperatures higher than 1470 K are needed to achieve nearly total reduction of substitutional Fe3+. Interestingly, iron favors the reduction of chromium. The composition of the Fe-Cr particles is strongly dependent on their size, the Cr content being higher in particles smaller than 10 nm.
引用
收藏
页码:229 / 235
页数:7
相关论文
共 19 条
[1]   SOL-GEL PREPARED NI-ALUMINA COMPOSITE-MATERIALS .1. MICROSTRUCTURE AND MECHANICAL-PROPERTIES [J].
BREVAL, E ;
DENG, Z ;
CHIOU, S ;
PANTANO, CG .
JOURNAL OF MATERIALS SCIENCE, 1992, 27 (06) :1464-1468
[2]   MOSSBAUER-SPECTRA OF NANOCRYSTALLINE FE AND FE-CR PARTICLES IN SOL-GEL-DERIVED SIO2 GLASS [J].
CHATTERJEE, A ;
DAS, D ;
CHAKRAVORTY, D ;
CHOUDHURY, K .
APPLIED PHYSICS LETTERS, 1990, 57 (13) :1360-1362
[3]   IRON ALUMINA INTERFACE IN CERAMIC MATRIX NANOCOMPOSITES [J].
DEVAUX, X ;
LAURENT, C ;
BRIEU, M ;
ROUSSET, A .
JOURNAL OF ALLOYS AND COMPOUNDS, 1992, 188 (1-2) :179-181
[4]  
DEVAUX X, 1991, CR ACAD SCI II, V312, P1425
[5]  
DEVAUX X, 1992, COMPOSITE MATERIALS, P209
[6]  
DEVAUX X, IN PRESS NANOSTRUCTU
[7]   MOSSBAUER-EFFECT STUDY OF CHARGE AND SPIN TRANSFER IN FE-CR [J].
DUBIEL, SM ;
ZUKROWSKI, J .
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 1981, 23 (02) :214-228
[8]   MOSSBAUER-EFFECT STUDY OF SPIN-DENSITY AND CHARGE-DENSITY CHANGES IN FE-AL ALLOYS [J].
DUBIEL, SM ;
ZINN, W .
PHYSICAL REVIEW B, 1982, 26 (04) :1574-1589
[9]  
GONG W, 1991, J APPL PHYS, V70, P5900
[10]  
Klomp J. T., 1978, Ceramurgia International, V4, P59, DOI 10.1016/0390-5519(78)90120-5