Acquisition of a Measurement System for Research and Education in Magnetic Heterostructures

这是DMR材料研究仪器项目授予明尼苏达大学双城分校的奖项。该奖项支持为磁性异质结构的研究和教育提供测量系统。该仪器将支持物理和材料科学四个领域的研究：a)磁性/半导体结构中自旋输运的新材料，b)新型磁性氧化物材料和异质结构，c)铁磁体/反铁磁体多层中的交换偏置，d)有机晶体中的二维导电性。该仪器结合了直流和交流磁强计，并在0.4至300 K的温度范围内和高达9 T的磁场中传输，将由参与生长和测量的学生使用。特别是，将开发新的自旋输运材料，包括铁磁半导体和半金属铁磁体。各种新的磁性氧化物材料，包括钴酸盐，如La1-x-SrxCoO3，将会被探索，目前关于氧化物用作自旋注入剂的工作将会继续。利用交换诱导各向异性和交换弹簧磁性控制多层材料矫顽力的微观机制将被研究。最后，将研究有机晶体中的低维输运，重点是超导性。DMR材料研究仪器项目授予明尼苏达大学双城分校的这一奖项，用于明尼苏达大学磁异质结构研究和教育的测量系统。磁性异质结构是由磁性材料（如铁）与其他金属、绝缘体甚至半导体结合形成的薄层“三明治”。根据特定的应用，磁性材料可以是三明治中的“肉”或“面包”。这些类型的异质结构已经在最新一代硬盘驱动器中使用，新仪器的一些研究将致力于理解这些新驱动器工作方式的微观机制。此外，将研究基于磁性氧化物的全新类型的结构。还将探索将磁体功能与晶体管中使用的半导体功能相结合的新一代结构。该仪器将供研究生和本科生使用，以加强他们在快速发展的材料物理领域的训练。

This is an award from the Instrumentation for Materials Research program in DMR to the University of Minnesota-Twin Cities. The award supports the acquisition of a measurement system for research and education in magnetic heterostructures. The instrument will support research in four areas of physics and materials science: a) new materials for spin transport in magnetic/semiconductor structures, b) novel magnetic oxide materials and heterostructures, c) exchange bias in ferromagnet/antiferromagnet multilayers and d) two-dimensional conduction in organic crystals. The instrument, which incorporates DC and AC magnetometry and transport over a temperature range of 0.4 to 300 K and in magnetic fields up to 9 T, will be used by students involved in both growth and measurements. In particular, new materials for spin transport, including ferromagnetic semiconductors and half-metallic ferromagnets, will be developed. A variety of new magnetic oxide materials, including cobaltates such as La1-x-SrxCoO3, will be explored, and current work on oxides used as spin injectors will be continued. Microscopic mechanisms for controlling coercivity in multilayers using exchange-induced anisotropy and exchange spring magnetism will be investigated. Finally, low-dimensional transport in organic crystals, with emphasis on superconductivity, will be studied. %%%This award from the Instrumentation for Materials Research program in DMR to the University of Minnesota-Twin Cities supports the acquisition of a measurement system for research and education in magnetic heterostructures at the University of Minnesota. Magnetic heterostructures are "sandwiches" formed by growing thin layers of a magnetic material, such as iron, in combination with other metals, insulators, or even semiconductors. Depending on the particular application in mind, the magnetic material can be either the "meat" or the "bread" in the sandwich. These types of heterostructures are already in use in the latest generation of hard disk drives, and some of the research the new instrument will be dedicated to understanding the microscopic mechanism that is ultimately responsible for the way in which these new drives work. Furthermore, entirely new types of structures, based on magnetic oxides, will be investigated. A new generation of structures, combining the functionality of magnets with those of semiconductors used in transistors, will also be explored. The instrument will be used by graduate students and undergraduates in order to enhance their training in the rapidly evolving field of materials physics.