文献类型：期刊文献

英文题名：Kinetics for reduction of aciculate ultrafine α-Fe₂O₃ particles to Fe₃O₄ particles

作者：Li, CZ; Hong, ZF

机构：[1]E China Univ Sci & Technol, Inst Tech Chem & Phys, Shanghai 200237, Peoples R China

年份：1997

卷号：134

期号：2

起止页码：248

外文期刊名：JOURNAL OF SOLID STATE CHEMISTRY

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000072115400005)】；

语种：英文

外文关键词：aciculate ultrafine particles; alpha-Fe2O3; reduction; kinetics; magnetic; nucleation and grain-growth model

摘要：The reduction kinetics of aciculate ultrafine alpha-Fe2O3 particles to Fe3O4 in a mixture of H-2 and N-2 were studied by using the temperature-programmed reduction technique, and the optimum conditions for reduction were investigated for preparation of magnetic powder. The reduction of aciculate ultrafine alpha-Fe2O3 particles to Fe3O4 was fitted to the nucleation and grain-growth model, and the reduction kinetic equation was written as d alpha/dt = 9.00 x 10(3) exp(-72.7 x 10(3)/RT) (1 - alpha)alpha(0.54). There existed a maximum reduction rate at the degree of transformation approximately equal to 0.34, which was considered to be a result of induction effects. The optimum temperature of aciculate ultrafine alpha-Fe2O3 particle reduction for magnetic powder preparation was 630-670 K. (C) 1997 Academic Press.