期刊
MATERIALS RESEARCH BULLETIN
卷 37, 期 2, 页码 221-234出版社
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/S0025-5408(01)00767-X
关键词
oxides; thermogravimetric analysis (TGA); differential scanning calorimetry (DSC); X-ray diffraction
The solid state reactions occurring in the mechanically activated System SrCO3-Fe2O3 (composition X-Fe (iron cationic fraction) = 0.5-0.923) have been studied. At X-Fe = 0.5, SrFeO2.5+x (brownmilletite) forms by annealing of the activated mixture at 850degreesC under nitrogen while the non-stoichiometric perovskite (SrFeO3-x) is the equilibrium product when annealing is performed under air. At X-Fe = 0.66 a mixture of SrFe2O4 and SrFe2O5 is the final product no matter what is the annealing atmosphere. The enthalpies of reaction at these composition have been determined. By increasing iron content (X-Fe = 0.8), the annealing at 850degreesC of the activated mixture leads to SrFe2O4, SrFe2O5 and SrFe12O19 (indicated in the following with the usual term of strontium hexaferrite). Finally at X-Fe = 0.923, SrFe12O19 is produced from the mechanically activated mixture at temperatures lower (approximate to800degreesC) than in the case of conventional solid state route. In the case of the last two compositions no reaction enthalpy could be determined as the process is too slow. (C) 2002 Elsevier Science Ltd. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据