Point-Contact Spectroscopy of Heavy Fermion Systems at Low Temperature.

低温重费米子系统的点接触光谱。

• 批准号: 63460023
• 负责人: KUNII Satoru
• 金额: $ 4.22万
• 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: 1988
• 资助国家: 日本
• 起止时间: 1988 至 1990
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-63460023/
• 关键词: Heavy Fermion; Point-contact; dense Kondo; Rare-earth hexaboride; 稀土類ヘキサボライド; 高濃度近藤物質; ポイントコンタクト・スペクトロスコピー; 希上類ヘキサボライド

Point-contact spectroscopy is now becoming a powerful tool for the investigation of the microscopic excitation or the electronic density of states of the bulk-materials.Following three points were proceeded by the Grant-in-Aid for Scientific Research (B).1. A point-contact spectrometer for low temperature was completed taking into account the reproducibility and the reliability of the data of point-contact spectroscopy.2. Various kinds of high quality single crystals of rare earth hexaborides were grown by the floating zone method. Many joint works with other institutions were carried out on these samples.3. Main results of our point-contact experiments are as follows. (1) It was concluded experimentally that there is a obvious difference between the barrier-type tunneling and the pure metal point-contact. (2) We decided the gap of valence fluctuating compound SmB_6 by the metal point-contact spectroscopy. (3) It was revealed by the point-contact spectroscopy that there should be some characteristic energy which is one order of magnitude larger compared with the Kondo temperature in the dense-Kondo CeB_6 compound. (4) We observed a voltage jump in the current-voltage characteristic of CeB_6 at low temperature under the magnetic field. We are now investigating the correlation of it with the Kondo gap in dense Kondo material.

点接触光谱现在已成为研究显微镜激发或散装状态状态的电子密度的强大工具。遵循三个点由科学研究赠款（B）进行了三个点。1。考虑到点触发光谱数据的可重复性和可靠性2。稀有地球的各种高质量的单晶由浮动区方法生长。在这些样品上进行了许多与其他机构进行的联合工作。3。我们的点接触实验的主要结果如下。 （1）在实验上得出结论，屏障型隧道和纯金属点接触之间存在明显的差异。 （2）我们决定了金属点触觉光谱法波动化合物SMB_6的差距。 （3）点接触光谱法揭示了应该存在一些特征能量，与密集的kondo ceb_6化合物中的亲托温度相比，它比一个数量级要大。 （4）我们观察到在磁场下低温下CEB_6的电流电压特性中的电压跳。现在，我们正在研究它与密集的近托材料中昆多差距的相关性。

项目成果

S.Kimura: "Anomalous Infrared Absorption in Rareーearth Hexaborides" Solid State Commun.75. 717-720 (1990)

S.Kimura：“稀土六硼化物的异常红外吸收”固态通讯717-720 (1990)。

S.KUNII: J.Phys.Soc.Japan. 57. 361-366 (1988)

S.KUNII：日本物理学会杂志。

S,Kunii: "Thermoelectric Power in Ce_<1ーx>La_xB_6 Kondo Systems" J,Magn,Magn,Mater. (1991)

S，Kunii：“Ce_<1ーx>La_xB_6 Kondo 系统中的热电”J，Magn，Magn，Mater（1991）。

S,Kunii: "Phonon Structure of LaB_6 by PointーContact Spectroscopy" J,Phys,Soc,Japan. 57. 361-366 (1988)

S，Kunii：“点接触光谱法的 LaB_6 声子结构”J，Phys，Soc，日本 57. 361-366 (1988)。

K.SUGIYAMA: J.Phys.Soc.Japan. 57. 1762-1770 (1988)

K.SUGIYAMA：J.Phys.Soc.Japan。