Raman spectroscopy study of in situ change in laser irradiated LiMn_2O_4  

作　　者：刘照军 韩礼刚 莫育俊 

机构地区：[1]Department of Physics and Electronic Information,Luoyang Normal College

出　　处：《Chinese Optics Letters》2012年第8期66-69,共4页中国光学快报（英文版）

基　　金：supported by the National Natural Science Foundation of China under Grant No. 10674041

摘　　要：A spinel LiMn2O4 is investigated via Raman spectroscopy at 514.5-nm excitation and X-ray diffraction. The dependence of Raman spectra on the different irradiated laser powers is determined and found to be different from that at 632.8-nm excitation. Based on our extensive analysis, our experimental results can be attributed to the laser heating effect, which reduces the Mn4＋ cation concentration in the local area. Consequently, the decrease in average Mn valence in the local area unavoidably induces the Jahn-Teller effect and local lattice distortion, which accounts for the evolution of the measured Raman spectra of spinel LiMn2O4.A spinel LiMn2O4 is investigated via Raman spectroscopy at 514.5-nm excitation and X-ray diffraction. The dependence of Raman spectra on the different irradiated laser powers is determined and found to be different from that at 632.8-nm excitation. Based on our extensive analysis, our experimental results can be attributed to the laser heating effect, which reduces the Mn4＋ cation concentration in the local area. Consequently, the decrease in average Mn valence in the local area unavoidably induces the Jahn-Teller effect and local lattice distortion, which accounts for the evolution of the measured Raman spectra of spinel LiMn2O4.

关 键 词：Jahn Teller effect Laser heating MANGANESE Manganese compounds Raman scattering Raman spectroscopy X ray diffraction 

分 类 号：TN24[电子电信—物理电子学]