In掺杂的GaFeO_3的磁性与拉曼光谱的研究  

EFFECT OF In DOPING ON MAGNETIC AND RAMAN SCATTERING PROPERTIES OF GaFeO_3

作　　者：吕艳娣[1] 高尚[1] 王晓雄[1] 程相义[1] 阮可青[1] 

机构地区：[1]中国科学技术大学物理系,合肥230026

出　　处：《低温物理学报》2013年第3期167-174,共8页Low Temperature Physical Letters

基　　金：国家重点基础研究发展计划项目(973计划;2012CB922003)资助的课题~~

摘　　要：本文用固相反应法制备了Ga1-xInxFeO3多晶样品,In的最大掺杂量为15%.XRD的精修结果显示随着In掺杂量的增加晶格常数和晶胞体积都增大,这是由于In的离子半径(1.44)远大于Fe、Ga的离子半径(0.64,0.62).亚铁磁转变温度由x=0时的201K减小到x=0.15时的157K,分析得到饱和磁化强度的变化趋势可能同Fe离子的分布有关.拉曼结果显示在温度大于亚铁磁转变点Tc时,由于体系的非谐相互作用,掺杂和温度升高均使所研究振动模的拉曼峰向低波数方向移动.样品在Tc附近的异常行为显示可能存在自旋-声子的耦合.Ga1-xInx-FeO3 polycrystalline materials have been prepared by a solid state reaction. The maximum Mn content amounts up to 15%. From the Rietveld refinement of X-ray powder patterns, the substitution of iron by indium leads to a increase in both the lattice parameters and unit cell volume, which caused by the crystal radii of indium（1.44A）larger than iron and gallium（0. 64A, 0. 62A）. The magnetic transiton temperature decrease as the indium increase, from 201K in x=0 reduced to 157K in x=0. 15, this is probably due to the occuption of Fe ion. As the sample was warmed from Tc to the room temperature , or indium substitution, the phonon wavenumbers of both manners decrease gradually. The decrease can be understood naturally in terms of anharmonic effect which has been reported previously. The sharp changes in studied modes are attributed to strong spin-phonon coupling in the magnetic phase below To.

关 键 词：晶格无序 磁化强度 磁转变温度 拉曼光谱 

分 类 号：O482.5[理学—固体物理]