Joint Research For Acoustic Phonon Spectroscopy and Electron-Lattice Interraction

超声声光谱、布里渊散射和热体积效应是研究重费米子材料、高Tc化合物、低维体系等强相关体系的重要探针。具有轨道角自由的量子系统的四极效应是本项目最重要的课题。利用超声测量方法研究了四极-应变相互作用引起的四极磁化率。采用实验和理论两种方法研究了近道化合物CeB6、Ce3Pd20Ge6和半导体Tm Te中具有反铁型构型的四极有序的特征性质。低温超声测量还研究了近藤体系CexLa1-xB6中近藤耦合与四极有序的相互作用。用费米表面上的电子态对稀土单晶的声德哈斯效应进行了研究。在低载流子体系中，电子耦合对体积应变有增强作用。CeRu2中横向模C_<44>的弹性软化及其与超导特性的相互作用是一个有趣的结果。在价态波动化合物Yb4As3的荷序、弹性软模、一维性质的磁激发Yb^<3+>离子等方面取得了进展。该项目的研讨会分别于1996年3月1日至3日在仙台市阿秋，1996年11月29日至30日在新田市浦浅举行。报告了许多有趣而重要的成果，对与会者的合作研究确实很有价值。

The acoustic spectroscopes of ultrasonic, Brillouin scattering and thermal volume effect are important probes to examine the strongly correlated systems of heavy fermion materials, high Tc compounds, low dimensional systems. The quadrupolar effect of the quantum system with orbital angular freedom is the most important subject of this project. The quadrupolar susceptibility due to the quadrupole-strain interaction of many 4f-electron systems were investigated by the ultrasonic measurements. The characteristic properties of the quadrupolar ordering with antiferro-type configuration in the Kondo compounds CeB6, Ce3Pd20Ge6, and semiconductor Tm Te were investigate by both experimental and theoretical approaches. The interplay of the Kondo coupling to the quadrupolar ordering in the Kondo system CexLa1-xB6 was also investigate low temperature ultrasonic measurements. The acoustic de Haas effect on rare earth monopunictides was performed to examined by the electronic states on the Fermi surfaces. The enhancement of the electron coupling to the volume strain in the low carrier systems was obtained. The elastic softening of transverse mode C_<44> in CeRu2 and interplay to the characteristic feature of the superconducting were interesting results. The charge ordering of the valence fluctuating compounds Yb4As3, the elastic soft mode, magnetic excitations Yb^<3+> ions with one dimensional character were progress in this project.The workshops of this project were hold as, (1) March 1-2-3,1996, Akyuu, Sendai, (2) November 29-30, December 1,1996, Urasa, Niigta. The presentations on many interesting and important resusts It were valuable indeed for cooperative researchs of participants.