Raman scattering study on Kondo semiconductors of CeRhSb and CeNiSn.

CeRhSb 和 CeNiSn 近藤半导体的拉曼散射研究。

• 批准号: 09640437
• 负责人: UDAGAWA Masayuki
• 金额: $ 2.05万
• 依托单位: HIROSHIMA UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09640437/
• 关键词: Kondo semiconductors; Raman scattering; Phonon; Magnetic and Phonon interaction; Pseudo-Gap; Spin-Gap; Electronic Raman scattering; スプンギャップ; 近籐半導体; CeRhSb; CeNiSn

The purpose of this research is to clarify the microscopic mechanism of the Kondo semiconductors of CeRhSb and CeNiSn by Raman scattering. The detailed polarization dependence of Raman scattering spectra has been measured in the temperature region between room temperature and 5K.The peaks, observed in the energy region between 0 and 250cm^-^1, are assigned as the phonons, judging from the results of the normal mode calculation. Among them, three phonons of CeRhSb and one of CeNiSn show the anomalous temperature dependence of their energy. Since these modes are the vibrations of Ce, the dependence shows the existence of the interaction between magnetic fluctuation and lattice vibration in the Kondo states. The broad background spectrum has been also observed in the Raman scattering spectra. Its intensity of the low energy region decreases below 30K.The spectral shape is well explained by the V-shaped state density of the pseudo-gap. The obtained parameters are similar to the reported values by specific heat and NMR.Such suppression of the hack-ground spectra of LaNiSn has not been observed. Therefore, the suppression of the low energy region of the back-ground spectra is originated from the appearance of the spin gap state due to the hybridization effect between the localized 4f and conduction electrons.

这项研究的目的是通过拉曼散射来阐明CERHSB和CENISN的近藤半导体的微观机制。拉曼散射光谱的详细极化依赖性已经在室温和5K之间的温度区域中进行了测量。从正常模式计算的结果来看，在0到250cm^ - ^1之间观察到的峰分配为声子。其中，CERHSB的三个声子和Cenisn之一显示了其能量的异常依赖性。由于这些模式是CE的振动，因此依赖性显示了围绕昆多状态中磁波动与晶格振动之间的相互作用的存在。在拉曼散射光谱中也观察到了广泛的背景光谱。其低能区域的强度降低到30k以下。光谱形状通过伪间隙的V形状态密度很好地解释。所获得的参数与尚未观察到lanisn的hack-ground光谱的特定热和NMR相似。因此，由于局部4F和传导电子之间的杂交效应，后台光谱的低能区域的抑制起源于自旋间隙状态的出现。

项目成果

Kohji Ohbayashi: "Temperature dependence of two-roton Raman spectrum of superfluid ^4He" Physical Review B. 58・6. 3351-3360 (1998)

Kohji Ohbayashi：“超流体^4He的双转子拉曼光谱的温度依赖性”物理评论B.58・6（1998）

N.Ogita, Y.Tsunezumi, J.Akimitsu, M.Udagawa: "Raman scattering study of Cu(Ge_<1-x>Si_x)O_3." Physica B. (in press). 3 (1999)

N.Ogita、Y.Tsunezumi、J.Akimitsu、M.Udakawa：“Cu(Ge_<1-x>Si_x)O_3 的拉曼散射研究。”

宇田川,永井,星野編: "物理学基礎実験第2版" 共立出版, 228 (1999)

宇田川、永井、星野等编：《基础物理实验第 2 版》Kyoritsu Shuppan，228 (1999)

S.Nimori, H.Hata, N.Ogita, S.Sakita, N.Kikugawa, F.Nakamura, T.Fujita, M.Udagawa: "Investigation of electron-phonon interaction in La_<2-x>Sr_xCuO_4 by Raman scattering." Physica B. (in press). 2 (1999)

S.Nimori、H.Hata、N.Ogita、S.Sakita、N.Kikukawa、F.Nakamura、T.Fujita、M.Udakawa：“通过拉曼散射研究 La_<2-x>Sr_xCuO_4 中的电子-声子相互作用

Shigeki Nimori: "Investigation of electron-phonon interaction in La_<2-x>Sr_xCuO_4 by Raman Scattering" Physica B. Total,2 (1999)

Shigeki Nimori：“通过拉曼散射研究 La_<2-x>Sr_xCuO_4 中的电子-声子相互作用”Physica B. Total,2 (1999)