准一维磁性材料的多铁性和磁电耦合效应

项目名称： 准一维磁性材料的多铁性和磁电耦合效应

项目编号： No.11204287

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 物理学I

项目作者： 赵霞

作者单位： 中国科学技术大学

项目金额： 28万元

中文摘要： 近年来在一些具有反铁磁交换作用的低维磁性材料中发现了多铁性和磁电耦合现象，其机制与常规的三维磁性材料中的多铁性有所不同，因此对这些材料的研究有助于更全面更深入地认识磁电现象的本质和探索新型多铁性材料。本项目以准一维的磁性材料为主要对象，在制备高品质单晶样品的基础上，利用低温强磁场下磁学、比热、电极化、介电等多种实验手段，研究低维磁性与磁电耦合的关系，包括：通过化学掺杂改变材料的结构和磁交换作用参数，结合宏观物性表征，深入研究这些材料量子态、磁结构和磁相变规律；同时进行电学性质的表征，研究铁电性、磁电耦合与量子磁性和磁相变的内在关联；并尝试在具有不同磁结构、磁交换作用特征的准一维磁性材料中探索新型的多铁性材料。这些实验工作有望为准确理解低维磁性材料的多铁性物理机制提供必要的实验基础。

中文关键词： 低维磁性材料；多铁性；磁电耦合；电极化；磁相变

英文摘要： Recently, some low-dimensional antiferromagnets have been found to exhibit multiferroics and magnetoelectric coupling, which may have different mechanisms from the multiferroics in usual three-dimensional magnetic materials. Investigations on these low-dimensional materials would be very helpful for the understanding of magnetoelectric phenomena and for finding new multiferroic materials. In this project, we choose quasi-one dimensional magnets as the objects of study. Based on growing high-quality single crystals and using various experimental techniques at low temepratures and in high magnetic fields, including magnetization, specific-heat, electric polarization and dielectric measurements, we plan to study the relationship between low-diemensional magnetism and magnetoelectric coupling. The main research contents include: (i) to change the crystals structures and magnetic interactions by chemical doping and study the quantum states, magnetic structures and magnetic phase transitions by using the characterizations of physical properties; (ii) to measure the electric properties for studying the relationship between ferroelectricity, magnetoelectric coupling and quantum magnetism and magnetic phase transitions; (iii) to try to look for some new multiferroic materials in some quasi-one-dimensional magnets with di

英文关键词： low-dimensional magnetic materials；multiferroics；magnetoelectric coupling；electric polarization；magnetic phase transitions