超高压下材料的磁阻特性研究

项目名称： 超高压下材料的磁阻特性研究

项目编号： No.50802033

项目类型： 青年科学基金项目

立项/批准年度： 2009

项目学科： 金属学与金属工艺

项目作者： 韩永昊

作者单位： 吉林大学

项目金额： 19万元

中文摘要： 本项目的研究目的是在金刚石对顶砧（DAC）上建立完备的超高压下材料的磁阻效应研究方法。通过超高压力下材料的磁阻变化，研究材料内部电子间的强关联作用，同时探讨超高压力下传导电荷与电子自旋的散射机制。本项目研究了金刚石对顶砧上磁阻效应的实验方法和科学问题，在技术层面上，解决了极微小样品区域内的磁场测量、样品制备、测量电极与样品间的集成等关键实验技术难点，实现了超高压下原位磁阻率测量，获得了压力对电子自旋影响的重要数据；在物理问题层面上，通过分析超高压下材料磁阻的变化，发现了一些新的压致磁阻现象，从电子自旋散射的角度解释了压致磁阻变化的基本物理过程，从而使现有的超高压下材料电学性质研究，从宏观的电阻率测量和对大量传导电荷集体运动的探讨，进入到更微观、更深入的电子自旋层次，拓展并完善了现有的研究方法。

中文关键词： 高压；磁阻；金刚石对顶砧；自旋；载流子

英文摘要： The purpose of this project is to establish a complete investigation method on diamond anvil cell (DAC) for the magnetic resistance effect study of materials under ultrahigh pressure, in which we mainly study the strong correlation on the interaction between electrons of the materials, and simultaneously discuss the scatering mechanism between the transporting charge and the electronic spin. The project has investigated the experiment method and the scientific issues on magnetic resistance effect study with DAC.On the technic level, we have got over a series of key technology, including magnetic field measurement, sample configuration, and the integration of electrodes and sample in an extremly samll sample chamber, with which in situ magnetic resistivity measurement under ultrahigh pressure was realized and the important data of high-pressure effect on electronic spin was achieved;On the level of scientific issue, via the analysis of the pressure dependence of magnetic resistance, we found some novel pressure-induced magnitice resistance effect, and from the pointview of electronic spin scatter, explained its basic physical process, based on which the project paved a way for the prsent study of electric properties of materias under ultrahigh pressure from the discussion about the macroscopical measurement of resistivity and the collective moment of large amount of charges to a more microcosmic and deeper level of investigation of electronic spins, and extented the present study methods.

英文关键词： high pressure;magnetic resistance; DAC;spin;charge carrier