Raman Active Phonons in RCoO3 (R=La, Ce, Pr, Nd, Sm, Eu, Gd, and Dy) Perovskites
WANG Wei-Ran1,2, XU Da-Peng1, SU Wen-Hui1,3,4, DING Zhan-Hui1, XUE Yan-Feng1, SONG Geng-Xin1,2
1Department of Physics, Jilin University, Changchun 130023
2Northeast China Institute of Electric Power Engineering, Jilin 132012
3Center for the Condensed-Matter Science and Technology, Harbin Institute of Technology, Harbin 150001
4International Center for Materials Physics, Chinese Academy of Sciences, Shenyang 110015
Raman Active Phonons in RCoO3 (R=La, Ce, Pr, Nd, Sm, Eu, Gd, and Dy) Perovskites
WANG Wei-Ran1,2;XU Da-Peng1;SU Wen-Hui1,3,4;DING Zhan-Hui1;XUE Yan-Feng1;SONG Geng-Xin1,2
1Department of Physics, Jilin University, Changchun 130023
2Northeast China Institute of Electric Power Engineering, Jilin 132012
3Center for the Condensed-Matter Science and Technology, Harbin Institute of Technology, Harbin 150001
4International Center for Materials Physics, Chinese Academy of Sciences, Shenyang 110015
Abstract： We examine RCoO3 (R=La, Ce, Pr, Nd, Sm, Eu, Gd, and Dy) perovskites prepared with the solid-state reaction method by Raman spectroscopy, and report the Raman active phonons in the RCoO3 perovskites crystallized in cubic symmetry for RCoO3 (R=La, Ce, Pr and Nd) and orthorhombic symmetry for RCoO3 (R=Sm, Eu, Gd, and Dy). It is found that the Raman spectra of RCoO3 perovskites are strongly dependent on the ionic radius of the rare earth elements, and the frequency shift of the most intense modes of the orthorhombic samples are correlated with some structural parameters such as Co--O bond distances, ionic radius of the rare earth elements and Jahn--Teller distortion. It is clear that Raman spectroscopy has the advantage of sensitivity to structure distortion and oxygen motion.
2005, Vol. 22 
