Molecular vibrations of the layered-perovskite cobalt oxides characterized by infrared and Raman spectroscopies coupled with crystal structure refinement

详细信息    查看全文

• 作者：Shengli Huang ; Keqing Ruan ; Zongqiang Pang ; Zhangming Lv ; Huiyan Wu ; Zhaochuan Shen ; Liezhao Cao ; Xiaoguang Li
• 关键词：C. Crystal structure and symmetry ; D. Optical properties ; E. Light absorption and reflection
• 刊名：Solid State Communications
• 出版年：2007
• 出版时间：January 2007
• 年：2007
• 卷：141
• 期：3
• 页码：150-155
• 全文大小：732 K

文摘

Molecular vibrations of the polycrystalline Nd_2−xSr_xCoO₄ are systematically characterized by powdered x-ray diffraction, Raman scattering and infrared spectra at different dopings as well as at different temperatures. Structural refinements reveal that all the specimens crystallize in the K₂NiF₄ structure with space group I4/mmm as is also confirmed by the phonon bands of Raman scattering and infrared transmittance. The frequency shifts of the phonon bands are found to be very well consistent with the elongation and/or contraction of the bond lengths. Moreover, for Nd_0.75Sr_1.25CoO₄, the phonon bands of the Raman active modes seem to retrace the evolutions of magnetic and structural temperature.