Materials World Network: The Magnetostructural Response in Heterostructured Systems: A US - UK Collaboration

这项由东北大学材料研究部金属材料和纳米结构计划和特别计划办公室颁发的材料世界网络奖是为了合成和研究等原子铁-铑(FeRh)化合物的异质结构薄膜，并绘制其多维相空间并识别低能路径，以定制在该化合物中发现的一阶反铁-铁磁相变和相关的功能响应。虽然已知一阶磁转变是一系列具有重要技术属性(巨磁电阻、巨磁热特性和巨磁形状记忆)的极端功能现象的基础，但关于控制这些反应的关键材料因素的知识仍然难以捉摸。在这个项目中，研究人员计划通过以下方法修改模型系统FeRh外延层中的相界：(1)使用额外的磁层来放大或抵消驱动相变的外加磁场；(2)通过衬底选择施加应力；以及(3)利用相间铁磁交换耦合。该项目的独特教育特点是扩大了美国和英国团队之间的科学学生交流，并为学生提供在研究中应用先进探测器的培训，如同步加速器X射线散射、中子散射和透射电子显微镜。这个项目的特色是基础研究，重点是一种非常罕见的材料--磁结构材料--的一种成员，这种材料显示出材料中的电子与组成其晶格的原子之间的密切相互作用。这种独特的布置使材料对物理扰动具有非凡的响应性，因此温度、磁场/电场或应变的微小变化可以在材料中驱动非常大的响应。因此，这种材料有望在先进的传感器中得到开发和潜在的应用，以监测环境条件，并通过计算机网络实现所谓的？智能？与能源管理和效率相关的网络。为了便于实验的清晰度，简单的磁性化合物FeRh将被制成薄膜，并在美国(东北大学，布鲁克海文国家实验室)和英国(利兹大学，ISIS/卢瑟福·阿普尔顿实验室)的合作实验室进行研究。有关教育机构的学生将参加大西洋两岸的研究交流，并将有机会接受基础科学以及使用同步加速器x射线散射、中子散射和透射电子显微镜等先进探测器的培训。

This Materials World Network award by the Metallic Materials and Nanostructures program and the Office of Special Program in the Division of Materials Research to Northeastern University is to synthesize and study heterostructured films of equiatomic Iron-Rhodium (FeRh) compound, and to map out its multi-dimensional phase space and identify low-energy pathways to tailor the first-order antiferro- to ferromagnetic phase transition and associated functional responses that are found in this compound. While first-order magnetic transitions are known to underlie an assortment of extreme functional phenomena with important technological attributes (colossal magnetoresistance, giant magnetocaloric character and giant magnetic shape memory), knowledge concerning key materials factors controlling these responses remains elusive. In this project, the researchers plan to modify the phase boundaries in model-system FeRh epilayers by: (1) employing additional magnetic layers to amplify or offset the applied magnetic field that drives the transition; (2) applying stress via substrate selection; and (3) exploiting interphase ferromagnetic exchange coupling. Unique educational features of the project are extended scientific student exchanges between the U.S. and the U.K. teams, as well as providing training to students in the application of advanced probes to the research such as synchrotron x-ray scattering, neutron scattering and transmission electron microscopy. This project features fundamental research focused on a member of a very rare class of materials -?magnetostructural materials? - that exhibit intimate interactions between the electrons in the material and the atoms that constitute its crystal lattice. This unique arrangement lends the material an extraordinary responsiveness to physical perturbations such that very small changes in temperature, magnetic/electric field or strain can drive a very large response in the material. Thus this class of materials is poised for development and potential application in advanced sensors to monitor environmental conditions and enable, via computer networking, so-called ?smart? networks with relevance to energy management and efficiency. To facilitate experimental clarity, the simple magnetic compound FeRh will be made in thin film form and studied at the partner laboratories in the U.S. (Northeastern University, Brookhaven National Laboratory) and in the U.K. (University of Leeds, ISIS/Rutherford Appleton Laboratory). Students from the educational institutions involved will participate in transatlantic research exchanges and will have the opportunity to be trained in fundamental science as well as in the use of advanced probes such as synchrotron x-ray scattering, neutron scattering and transmission electron microscopy.