The Study for Heavy Fermion State in f- electron pnictides

f电子磷族元素中重费米子态的研究

基本信息

批准号：
03452027
负责人：
SUZUKI Takashi
金额：
$ 4.1万
依托单位：
TOHOKU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1991
资助国家：
日本
起止时间：
1991 至 1992
项目状态：
已结题

项目摘要

We could make remarkable development for the extensive fundarmental properties of Ce monopnictides under ultra high pressure; The transport properties and the change of the Fermi surfaces area under high pressure have been measured. The Fermi surfaces area of the reference system of LaSb increased with increasing pressure as in the usual case. However that of CeAs decreased with increasing pressure. The latter case is clearly due to f electron effect and bring the interesting problem to be solve The neutron diffraction and scattering revealed the variation of complicated magnetic structure and crystalline field splitting with increasing pressure. The magnetization for CeP single crystal have been measured up to 60T and showed nearly 10 step magnetization at the magnetic field just same time for Landau level crossing of the hole Fermi sphere and attracted many interest for this new phenomena. The discovering of largest fermi surface in CeSb by accoustic dHvA effect proved the rightness of the p-f mixing theory. The success of very pured single crystal of LaAs can bring us to new stage ofd extremly low carrier system of 10-4 order of carrier number and expect to clearfy the behavior of the quantum limit of Landau motion for avaiable high magnetic field. The dHvA measurement for the most typical heavy Fermion state of low carrier system of YbAs and could detect the electron and one hole Fermi surface with effective mass below 1 and were not consistent with large coefficient of the electronic specific heat capacity. It should be another hole Fermi surface with very large mass up to several thousand. This large massenhancement is particular point of low carrier system and not seen in usual mettallic heavy Fermion systems. The most impressive discovery in this project is the heavy Fermion state of insulating state in Sm3X4 and suggest the fundermental revolution of usual heavy Fermion concept.

我们可以为在超高压力下Ce Monopnictes的广泛的质地特性做出显着发展；已经测量了在高压下的运输特性和费米表面区域的变化。如通常情况下，LASB参考系统的费米表面面积随着压力的增加而增加。但是，CEAS随着压力的增加而降低。后一种情况显然是由于f电子效应引起的，并带来了有趣的问题，可以解决中子衍射和散射，这表明复杂的磁性结构和晶体场随着压力的增加而变化。 CEP单晶的磁化测量已被测量至60吨，并在同一时间在磁场上显示了近10个步骤的磁化，这是孔费米球体的Landau水平穿越，并引起了这种新现象的许多兴趣。通过Acoustic DHVA效应发现CESB中最大的费米表面证明了P-F混合理论的正确性。非常纯净的LAA的单晶成功可以使我们进入10-4个载波数量的极低载体系统的新阶段，并期望清除Landau运动的量子限制的行为，以避免使用高磁场。 YBA的低载体系统最典型的重型费米的DHVA测量值，可以检测电子和一个孔费米表面，有效质量低于1，并且与电子特异性热容量的大系数不一致。它应该是另一个孔费米表面，质量很大，可达几千。这个大型的Massenhancement是低载体系统的特殊点，在通常的荟萃繁重的费米昂系统中没有看到。该项目中最令人印象深刻的发现是SM3X4中绝缘状态的沉重效率状态，并提出了通常的沉重费米昂概念的庆祝革命。