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De Haas-van Alphen Effect of Heavy Electron Systems with non-Fermi Liquid behavior

具有非费米液体行为的重电子系统的德哈斯-范阿尔芬效应

基本信息

批准号：
11640356
负责人：
MAEZAWA Kunihiko
金额：
$ 1.92万
依托单位：
TOYAMA PREFECTURAL UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

项目摘要

The Fermi surface study of CeNi2Ge2, which is a heavy electron system showing non-Fermi liquid behavior, by means of de Haas-van Alphen (dHvA) effect was intended. The method of crystal growth with very low residual resistivity was studied. Further, we perfoemed to measure the dHvA effect of the reference material LaNi2Ge2.RESULTS : A good quality single crystals could be obtained in the following conditions : 1) Pre-purification of the raw material of Ce using electro-transport method. 2) Growth along the [001] direction using the seed. For the best specimen, which was only obtained at the position up to 20 mm from the neck point of the single crystal rod, the residual resistivity was 1.5 μΩ cm and the half width of the X-ray rocking curve, (004) reflection, was 0.2 degrees. The dHvA effect of CeNi2Ge2 could not be observed, probably due to the heavy electron masses. We will try to observe at a temperatures lower than 3He temperature in a future. On the other hand, we suceeded to measure the dHvA effect of LaNi2Ge2, and compared to the Fermi surfaces calculated, obtaining very good agreement between the experiment and the band calculaion.We also studied the magnetic correlation and the superconductivity, using the inelastic nutron scattering and the electrical resistivity. It was found the weak antiferromagnetic correlation exists at temperatures lower than 30 K, and the superconductivity also was found at ambient pressure and at pressures from 2 GPa to 5 GPa at temperatures lower than 300 mK.

CeNi2Ge2 是一种表现出非费米液体行为的重电子系统，旨在通过德哈斯-范阿尔芬 (dHvA) 效应进行费米表面研究。研究了极低残余电阻率的晶体生长方法。此外，我们还测量了参考材料LaNi2Ge2的dHvA效应。结果：在以下条件下可以获得高质量的单晶： 1）采用电迁移法对Ce原料进行预纯化。 2) 使用种子沿[001]方向生长。对于仅在距单晶棒颈点20mm的位置处获得的最佳样品，残余电阻率为1.5μΩ·cm，并且X射线摇摆曲线（004）反射的半宽度为0.2度。无法观察到 CeNi2Ge2 的 dHvA 效应，可能是由于电子质量重。未来我们将尝试在低于3He温度的温度下进行观测。另一方面，我们成功测量了LaNi2Ge2的dHvA效应，并与计算的费米面进行了比较，实验与能带计算之间取得了很好的一致性。我们还利用非弹性中子散射和电阻率研究了磁关联和超导性。发现在低于30 K的温度下存在弱反铁磁相关性，并且在环境压力和低于300 mK的温度下2 GPa至5 GPa的压力下也发现了超导性。