Pseudobinary phase dicgram and larg high-quality single crystal growth of thallium-based cuprate high temperature superconductors

铊基铜酸盐高温超导体的伪二相图及大型高质量单晶生长

基本信息

批准号：
10450003
负责人：
HASEGAWA Masashi
金额：
$ 9.02万
依托单位：
University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 1999
项目状态：
已结题

项目摘要

Main topics obtained in this study are described below.(1) Pseudobinary phase diagrams of the bismuth-based cuprate high temperature superconductors, which may be similar to that of that of the thallium-based ones, have been clarified by in-situ high temperature X-ray diffraction measurements. stability of a new unstable bismuth cuprate has been also clarified. Crystallization processes of amorphous bismuth-based cuprate have been clarified. The activation energy for the crystallization has been estimated by the time-resolved X-ray diffraction measurements.(2) Vertical-type electric furnace and closed-atmosphere growth technique for the thallium-based cuprate high temperature superconductors have been newly developed. A new growth cell for the thallium-based cuprate high temperature superconductors, which are toxic and have high vapor pressure, has been developed.(3) Large high-quality single crystals of the thallium-based cuprate high temperature superconductors, especially thallium-oxygen double layered cuprates, have been grown. Heavily and slightly overdoped single of the thallium-oxygen double layered cuprate high temperature superconductor have been obtained by annealing under the controlled atmosphere of oxygen partial pressure. The other thallium-based cuprate high temperature superconductors are also now tried to grow.(4) Vortex melting points, irreversible magnetic fields and upper critical fields of the grown crystals have been determined. Vortex behaviors in the cuprate superconductors have been clarified and some new results to resolve a mechanism of the high temperature superconductivity are also obtained. Investigations on the scanning tunneling microscopy, photoemission measurements, de Haas-van Alphen effect measurements using the grown crystals are now going on with many domestic and foreign collaborators.

在下面介绍了这项研究中获得的主要主题。（1）基于二晶的Cuprate高温超导体的伪相图，这可能与基于thallium的基于Thallium的铜相图已通过SITU高温阐明X射线衍射测量。新的不稳定二晶铜纸的稳定性也已阐明。已经澄清了基于非晶态晶木的铜质的结晶过程。通过时间分辨的X射线衍射测量值估算了结晶的活化能。（2）（2）新开发的基于thallium的Cuprate高温超导体的垂直型电炉和闭合大气生长技术是新开发的。已经开发了一个有毒且具有高蒸气压的硫酸盐高温高温超导体的新生长电池。双层的铜层已经长大了。通过在氧局部压力的受控大气下退火，获得了thallium-oxygen双层高温超导体的大量和略微过高的单个高温高温超导体。现在还尝试了其他基于thallium的丘陵高温高温超导体。（4）已经确定了生长晶体的涡流熔点，不可逆的磁场和上临界场。丘比特超导体中的涡流行为已经阐明，还获得了一些新的结果，以解决高温超导性的机制。现在，许多家庭和外国合作者正在进行有关使用成年晶体进行扫描隧道显微镜，光发射测量，DE HAAS-VAN ALPHEN效应测量的研究。