利用中子衍射技术研究锰基金属间化合物交换偏置效应

项目名称： 利用中子衍射技术研究锰基金属间化合物交换偏置效应

项目编号： No.11504348

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 数理科学和化学

项目作者： 夏元华

作者单位： 中国工程物理研究院核物理与化学研究所

项目金额： 24万元

中文摘要： 交换偏置在基础研究和实际应用两个方面都有着广泛的前景，是磁学领域的研究热点；中子衍射技术是表征材料晶体结构尤其是磁结构、区分近邻元素的最有效工具。本项目依托于“中国绵阳研究堆”中子散射科研平台，以中子衍射技术为主要研究手段，从原子和自旋层面研究锰基金属间化合物（Y(Mn,M)2, Y(Mn,M)12, Y2(Mn,M)12, Y6(Mn,M)23, M=Fe, Co, Ni）的交换偏置效应。本项目拟采用熔炼、快淬等手段及最佳热处理工艺，制备出高质量单相锰基合金；通过常规手段（XRD、电镜和磁性测量等）对样品进行表征，找出晶体结构和成分与交换偏置场的关系，得到具有巨大交换偏置效应的同质合金材料；通过变温中子衍射手段，得到材料的磁结构，再利用微磁学模拟，建立有效的物理模型，从而从原子和自旋层面解释交换偏置的物理机制。为寻找具有应用价值的交换偏置体系提供理论和技术支撑。

中文关键词： 交换偏置；中子衍射；交换耦合作用；锰基金属间化合物；微磁学模拟

英文摘要： Exchange bias (EB) is one of the hot topics in magnetic field, which is widely applied to the fundamental researches and applied disciplines. Neutron diffraction technique is the best effective method to characterize the structure of material, especially for the magnetic structure and to distinguish between neighbor elements. The project, relying on the neutron scattering research platform at CMRR (China Mianyang Research reactor) and using the neutron diffraction technique as the main research method, investigates the EB effect of the manganese based intermetallic compounds（Y(Mn,M)2, Y(Mn,M)12, Y2(Mn,M)12, Y6(Mn,M)23, M=Fe, Co, Ni）on atoms and spin scale. The project aims to prepare high quality single Mn-based alloys by using melting, rapid quenching and optimum heat treatment processes; then the conventional means (XRD, electron microscopy and magnetic measurements) are used to characterize the relationship between the crystal structure, composition and the EB field and to search the homogeneous alloy with large exchange bias field; lastly, using the variable temperature neutron diffraction and micro magnetic simulation, establishes the effectively physical model to explain the physical mechanism of the EB. The project can provide theoretical and technical support to seek the EB material system with great application value.

英文关键词： Exchange bias;Neutron diffraction;Exchange coupling interaction;Mn-based intermetallic compound;Micromagnetic simulation