Nanocrystallization Kinetics and Induced Anisotropy in Soft Magnetic Nanocomposites

该奖项由材料研究部授予卡内基梅隆大学，旨在研究软磁纳米复合材料的合成、结构和性能关系，这些材料在能源转换和数据存储方面显示出良好的应用前景。凭借这一奖项，McHenry和Laughlin教授将研究以下内容：(1)加深对纳米结晶动力学作为控制磁性微结构工具的现有理解；以及(2)确定纳米复合材料的微结构(包括磁场和磁畴结构引起的微结构变化)与软磁性能之间的关系。研究将在以下方面发展对纳米复合软磁材料的合成、结构和性能关系的基本理解：(A)纳米晶化动力学模型的改进；(B)纳米晶化过程中发生的化学分配的模拟及其在晶间磁耦合的温度依赖性中的作用；以及(C)旨在阐明诱导磁各向异性的微观机制的微观结构观察和磁性测量。这些被称为HITPERM的基于铁-钴-M-硼-铜(其中金属可以是Nb、Z或Hf)的软磁纳米复合材料在高温、高频感应器件和数据存储中的感应元件中具有广阔的应用前景。电力电子元件的小型化必须考虑电感元件以及频率响应(功率密度、损耗)和热管理问题。在垂直记录介质上的热辅助写入需要高温/高感应磁衬层和写头以及自旋阀传感器中的低噪声、软磁层。磁性纳米复合材料的开发将得益于对磁性纳米结构/性质关系的基本了解。科学互动包括佐治亚理工学院和国家高场磁实验室在高场纳米结晶实验方面的活动，以及国家材料研究所(日本筑波)场离子显微镜方面的活动。研究工作将与旨在教授研究方法和向本科生交流最新技术的教育倡议相结合。研究人员目前教授应用磁学和磁性材料的研究生课程。本课程大纲将被修订，以提供本科学分，作为本科课程的一部分，作为与磁性材料轨道的接口。将就课程内容征询希捷公司和Magnetics，Inc.这两家当地行业的意见。这项工作与美国空军和美国国家航空航天局共同出资开发高频高温感应设备。

This award by the Division of Materials Research to Carnegie Mellon University is to study synthesis, structure and property relationships in soft magnetic nanocomposite materials that show promise for applications in energy conversion and data storage. With this award, Professors McHenry and Laughlin will study the following: (1) furthering present understanding of nanocrystallization kinetics as a tool for controlling magnetic microstructures; and (2) determining the relationship between microstructure (including magnetic field and domain structure induced microstructural changes) and soft magnetic properties of nanocomposite materials. Research studies will develop fundamental understanding of the synthesis, structure, and property relationships in nanocomposite soft magnetic materials in terms of: (a) refinement of models of the kinetics of nanocrystallization; (b) modeling chemical partitioning that occurs during nanocrystallization and its role in the temperature dependence of intergranular magnetic coupling; and (c) microstructural observations and magnetic property measurements aimed at elucidating the microscopic mechanisms for inducing magnetic anisotropy. These soft magnetic nanocomposites based on iron-cobalt-M-boron-copper (where the metal could be niobium, zirconium or hafnium) called HITPERM have promise for application in high temperature, high frequency inductive devices and inductive components in data storage. Miniaturization of power electronic components must consider inductive components and issues of frequency response (power density, losses) and thermal management. Thermally assisted writing on perpendicular recording media requires high temperature/high induction magnetic underlayers and write heads and low noise, soft magnetic layers in spin valve sensors. Magnetic nanocomposite materials development will benefit from a fundamental understanding of magnetic nanostructure/property relationships. Scientific interactions include activities at Georgia Institute of Technology and the National High Field Magnetic Laboratory on high field nanocrystallization experiments and National Institute for Materials Research (Tsukuba, Japan) for field ion microscopy. Research efforts will be coupled to educational initiatives aimed at teaching research methodology and communicating state of the art to undergraduates. The investigators at present teach a graduate course on Applied Magnetism and Magnetic Materials. This course syllabus will be revised so as to offer undergraduate course credit as an interface to the Magnetic Materials Track as part of the undergraduate curriculum. Two local industries, Seagate Corp. and Magnetics, Inc. will be consulted as to course content. This work couples with U. S. Air Force and NASA funded efforts to develop high frequency, high temperature inductive devices.