LaFe_(1-x)Cr_xO_3系列氧化物的EXAFS研究  

Study on Perovskite Oxides LaFe_(1-x)Cr_xO_3 by EXAFS

作　　者：王嘉鸥[1] 杜永华[2] 奎热西[2] 洪才浩[2] 谢亚宁[2] 胡天斗[2] 

机构地区：[1]兰州大学,兰州730000 [2]中国科学院高能物理研究所,北京100049

出　　处：《高能物理与核物理》2007年第1期101-103,共3页High Energy Physics and Nuclear Physics

基　　金：国家自然科学基金(10074063;10274084)资助~~

摘　　要：采用固相反应法,制备了钙钛矿结构氧化物LaFe_(1-x)Cr_xO_3较宽范围内(x=0．0—0．7)的系列单相样品,并测量了各样品的X射线衍射谱(XRD)和扩展X射线吸收精细结构(EXAFS)谱．通过对XRD的分析样品均为钙钛矿结构正交相,同时晶格常数随着掺杂量x的增加而减小．通过对EXAFS的分析和研究得到在LaFe_(1-x)Cr_xO_3氧化物中Fe-O键长和Fe-La键长随掺杂浓度x的变化,发现Fe-La键长发生比较大的变化,说明La在体系掺杂中对结构的稳定起到重要作用．Perovskite oxides LaFe1-xCrxO3 were synthesized by solid state reaction method. X-ray powder diffraction was tested to characterize the crystalline structure of the samples. The result indicates that the samples are single orthorhombic phase. The lattice parameter decreases with the Chromium concentration. The extend X-ray absorption fine structures （EXAFS） of the Fe K-edge as a function of doping level x show that the Fe-La bonds distance decreases dramatically. This suggests that Lanthanum is very important for the stability of the whole LaFe1-xCrxO3 structure.

关 键 词：ABO3(钙钛矿结构) XRD(X射线衍射谱) EXAFS(扩展X射线吸收精细结构谱) 

分 类 号：O482[理学—固体物理]