掺钐和掺镧铁酸铋的拉曼光谱

Raman spectra of Sm-doped and La-doped BiFeO_3

本文对Bi1-xSmxFeO3和Bi1-xLaxFeO3样品的拉曼光谱进行了研究,结果表明当掺Sm量达15%时,170cm-1和272cm-1模消失,287cm-1新模出现,Bi1-xSmxFeO3样品发生了三角到三斜的结构相变;而当La量达30%时,175cm-1、219cm-1和348cm-1模消失,Bi1-xLaxFeO3样品才发生三角到正交的结构相变。这归因于Sm的有效离子半径与Bi的差别较大。掺杂导致的拉曼峰蓝移归因于离子间的作用增强。

The Raman spectra of Bi1-xSmxFeO3 and Bi1-xLaxFeO3 were discussed.When Sm content reached 15%,170 and 272 cm-1 modes disappeared,287 cm-1 mode appeared,the Bi1-xSmxFeO3 structure transforms from trigonal into triclinic.However,as La content reached 30%,175,219 and 348 cm-1 modes disappeared,the Bi1-xLaxFeO3 structure transforms from trigonal into orthorhombic.This is ascribed to large difference between Sm and Bi radius.Blue shifts of Raman frequencies are attributed to increase in action between ions with doping.