极端条件下物质磁性的原位测量

In-situ magnetic measurements of substances under extreme conditions

温度和压力均是决定物质存在状态的基本热力学要素.低温和高压是现代科学实验最重要的极端条件,为物理、化学、材料和生物等多学科研究提供了新途径,对于发现和认识新现象、揭示新规律具有重要作用.极端条件下物质的磁性研究是极端条件研究的重要分支,不仅给出了物质在极端条件下的磁性变化,而且是研究高温超导体的重要手段.本文阐述了高压下物质磁化率和超导转变温度测量的原理和方法,并简要介绍了设计、搭建的低温高压下物质磁性原位测量系统.利用此系统测量了铁在高压下的磁性转变以及钇钡铜氧样品在高压下的超导转变温度.

Temperature and pressure are the two most important thermodynamic elements, which determine the existent state of substance. Low temperature and high pressure are significant and key extreme conditions in the modern experimental science, providing new routes for many subjects such as physics, chemistry, materials and biology, and playing an important role in finding new phenomena. The magnetic research under extreme conditions is an important branch of the study of the extreme conditions, which not only presents the magnetic changes of the material under extreme conditions, but also is an important means to explore the high temperature superconductors. In this article, we elaborate the principle and method of measuring the magnetic susceptibility and superconducting transition temperature under high pressure. The in-situ magnetic measurement system under high pressure and low temperature is also briefly introduced, designed and installed by ourselves. Using the in-situ magnetic measurement system, the magnetic transition of iron and the superconducting transition temperature of the yttrium barium copper oxide sample under high pressure are measured.