压力调控下铁基超导体的磁有序、晶体结构以及超导性质的演化及其关联研究

项目名称： 压力调控下铁基超导体的磁有序、晶体结构以及超导性质的演化及其关联研究

项目编号： No.11474344

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 数理科学和化学

项目作者： 望贤成

作者单位： 中国科学院物理研究所

项目金额： 98万元

中文摘要： 压力可以在不引入无序情况下对材料进行物性调控，并在铁基超导的研究过程中发挥了重要作用, 是调控超导性质的有效手段。压力在逐渐抑制铁基超导母体相磁有序的基础上诱导超导电性，研究压力调控下磁有序与超导序之间演化及关联将为理解压力诱导高温超导物理机制提供重要信息。本项目计划利用现有的高压极端表征技术以及大科学研究平台（如高压低温原位输运性质测量、高压原位同步辐射穆斯堡尔谱技术以及高压原位同步辐射X光衍射等）研究不同体系铁基超导母体相的磁有序、晶体结构、超导性质在压力调控下的演化及其相互之间的关联；研究上述体系在压力调控下是否存在量子临界点以及在量子临界点附件新颍的物理现象；从压力调控下晶体结构参量的演化来研究压力调控超导行为的结构起源；绘制不同体系铁基超导母体相在压力调控下完整的超导相图。通过上述研究，进一步促进对铁基超导体系中压力诱导/调控高温超导物理机制的认识。

中文关键词： 高压物理；铁基超导体；量子临界点

英文摘要： High pressure can modify effectively the crystal or electronic structure and then the properties of material without inducing disorder effect. It plays an important role in the research of iron based superconductors. Pressure can gradually suppress the magnetic and structural transition temperatures of the parent iron based superconductors and then induce superconductivity. There is a competing between the magnetic order and the superconducting order, so the research of pressure dependence of the two orders and their couple are helpful to uncover the superconducting mechanism. In this proposal, for the parent compounds of different iron based superconductors, we plan to use high pressure techniques, such as in-situ high pressure resistivity measurement, in-situ high pressure synchrotron M?ssbauer and in-situ high pressure synchrotron X-ray diffraction, (1) to study the evolution of magnetic order, structural transition and superconducting properties and their correlations tuned by high pressure; (2) to study whether the quantum critical point exists when the magnetic order is suppressed by pressure and study the phenomena near the quantum critical point and their correlations with superconductivity;(3) to study the pressure dependence of structural parameters and their correlations with superconductivity to uncover the structural origin of pressure tuning superconductivity; (4) finally to present the complete P-T phase diagrams of different iron based superconductor systems. Based on the above efforts it is hoped to help understanding the mechanism of pressure tuning the superconductivity.

英文关键词： high pressure physics;iron based superconductor;quantum critical point