Joint Research For Acoustic Phonon Spectroscopy and Electron-Lattice Interraction

超声、布里渊散射和热容效应的声谱是研究重费米子材料、高T_c化合物、低维体系等强关联体系的重要探针。具有轨道角自由度的量子系统的四极效应是本项目最重要的课题。通过超声测量研究了多个4f电子系统的四极-应变相互作用引起的四极极化率。用实验和理论相结合的方法研究了近藤化合物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。研究了CexLa1-xB6体系中Kondo耦合对四极有序的相互作用，并进行了低温超声测量。利用费米表面的电子态研究了稀土单环化合物的声学De Haas效应。得到了低载流子系统中电子耦合对体应变的增强作用。CeRu2中横模C&lt；44&gt；的弹性软化及其与超导特性的相互作用是有趣的结果。该项目在价态波动化合物Yb4As3的电荷有序、弹性软模、一维特征的磁激发Yb^&lt；3&gt；离子等方面取得了进展。该项目的工作坊于1996年3月1日至2日至3日在仙台阿克育举行，(2)1996年11月29日至30日在尼格塔乌拉萨举行。对许多有趣和重要的成果所作的介绍确实对参与者的合作研究很有价值。

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.