钒氧化物中金属-绝缘体转变相关的问题研究

项目名称： 钒氧化物中金属-绝缘体转变相关的问题研究

项目编号： No.11474111

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： 袁松柳

作者单位： 华中科技大学

项目金额： 100万元

中文摘要： 钒氧化物特别是VO2所表现出的金属-绝缘体转变与其自身的特殊结构相变密切相关，对其起因的了解涉及到很多基础性问题，同时伴随相变而发生的光学、电学性能的突变使之展现出巨大的应用前景。本项目以VO2为主要研究对象，一是通过V位不同离子半径的过渡金属的掺杂以及氧含量的控制，从电子或空穴引入以及晶格畸变的角度，探讨实现转变温度的有效调控的可能；二是将电子自旋共振和超强磁场（~75T）应用于这类材料的研究，基于相变前后电子自旋共振谱以及超强磁场下电子输运和磁等性质的变化规律的分析，探讨了解这类氧化物中金属-绝缘体转变的起因；三是选择合适的第二相材料，如铁电、铁磁或多铁等材料，将第二相材料同钒氧化物一起以适当的结合方式形成二相系统，利用钒氧化物结构相变引起的应力变化实现对铁电材料的铁电性能、铁磁材料的磁性能以及多铁材料的磁电耦合效应等的调控。

中文关键词： 金属绝缘体转变；结构相变；性能调控；强磁场；电子自旋共振

英文摘要： The mental-insulator transitions in vanadium oxides, especially in VO2, are closely related to their specific structure transitions. Understanding of their causes involve many fundamental physical problems, while the dramatic shifts of optical and electrical properties which accompanied with the phase transition show so great application prospect. This project takes VO2 as the main object of study. First, dope various transition metals with different ionic radius and control the oxygen content to bring in electron or hole，and change the lattice stress, to discuss the possibility of effectively regulating transition temperature. Second, use the ESR and the ultra-high magnetic field (~75T) to do research on such materials, based on the electron spin resonance spectroscopy before and after phase transition, the electronic transport and the magnetic properties under ultra-high magnetic field, to explore the causes of the mental-insulator transition in these oxides. Third, choose the appropriate second phase materials, such as ferroelectric materials, ferromagnetic materials and multiferroic materials to form two-phase systems with vanadium oxides in suitable combination, and use the stress variation along with the structure transition to achieve the control of ferroelectric properties of ferroelectric materials, ferromagnetic properties of ferromagnetic materials, and the magneto-electric coupling effect of multiferroic materials.

英文关键词： metal-insulator transition;structural phase transition;control of physical properties;strong magnetic field;electron spin resonance