Research on Spinel Trpe Cu sulfide Superconductors

尖晶石Trpe硫化铜超导体的研究

基本信息

批准号：
06640481
负责人：
MIYATANI Kazuo
金额：
$ 1.34万
依托单位：
Ehime University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1996
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-06640481/
关键词：
thiospinels copper sulfides CuCo_2S_4 CuV_2S_4 CuRh_2S_4 itinerant antiferromagnet superconductors electron correlation spinels cupper sulfides antiferro super conductors spin correlation Jahn-Teller SCR theory copper sulfide

项目摘要

Superconductivity of Cu oxide high temperaturu superconductors is based on the electronic state of Cu(3d^9)-O(3p^6).To extend the understanding about the origin of the superconductivity, it is quite interesting to find basic properties of Cu(3d^9)-S(3p^6) orbits of Cu sulfide superconductors with low anisotropy. We performed exploratory work about various spinel type Cu sulfide superconductors, and found that the Cu_<1+X>Co_<2-X>S_4(x=0-0.5) system with a low spin state of Co^<3+>(3d^6) shows antiferromagnetic behavior at 20K and superconductor transition at 5K.Research activity was focused on this system and related Cu salfide materials of (Cu, M)Co_2S_4(M=Ni and Co), Cu[Cu_XRh_<2-X>]S_4 and CuV_2S_4. Hard work was needed to develop reproducible process of sample synthesis, and was a measure reason for the research schedule postponed a year. In fact, even today, the sample is produced in our laboratory only in the world in spite the unique material was found 5 years ago. The high quality sample are now available, and the magnetism and superconductivity data are being renewed well.Inthis program, material synthesis, crystallographic data, electronic conductivity, superconductivity and microscopic NMR data were studied with the collaborate teams and obtained very effective yields. Material synthesis and the basic properties were done in Ehime University, some low temperture measurements in Solid State Technical Institute for Tokyo University, standard NMR study in Tokushima University and advanced NMR study in Kobe University. As the result, various unique phenomena and physics were obtained to explain the superconductivity, spin correlation, and electron correlation in the Cu(3d)-S(3p) system, and we have published 12 major technical papers.Low temperature specific heat, neutron diffraction, Seebeck effect and higt-pressure effect are also being studied and stimulating results are being given. These are targeted to explore in near future.

Cu氧化物高温超导的超导性基于Cu的电子状态（3D^9）-o（3p^6）。为了扩展对超导性起源的理解，找到Cu的基本特性非常有趣（ 3D^9）-s（3p^6）硫化物超导体的轨道低。我们进行了有关各种尖晶石类型Cu硫化物超导体的探索性工作，发现Cu_ <1+x> co_ <2-x> s_4（x = 0-0.5）系统具有较低的co^<3+>的旋转状态（ 3D^6）显示了20K处的抗磁性行为，而在5K处的超导体过渡都集中在该系统和相关的Cu Salfide材料（Cu，M）CO_2S_4（M = Ni和Co），Cu [Cu_xrh_ <2-x> <2-x> <2-x> <2-x> ] S_4和CUV_2S_4。需要努力工作来开发可再现样品合成过程，这是研究时间表的衡量理由。实际上，即使在今天，该样本还是在我们的实验室中生产的，仅在5年前就发现了独特的材料。现在可以使用高质量的样本，并且磁性和超导性数据正在很好地续签。在此计划，材料合成，晶体学数据，电子电导率，超导性和显微镜NMR数据与协作团队一起研究并获得了非常有效的收率。材料合成和基本特性是在埃希姆大学（Ehime University）完成的，在东京大学固态技术研究所，Tokushima University的标准NMR研究以及科比大学的高级NMR研究。结果，获得了各种独特的现象和物理学，以解释Cu（3D）-S（3P）系统中的超导性，自旋相关和电子相关性，我们发表了12个主要的技术论文。还研究了衍射，Seebeck效应和Higt压力效应，并给出刺激结果。这些目标是在不久的将来进行探索。