Nanocrystallization Kinetics and Induced Anisotropy in Soft Magnetic Nanocomposites

该奖项由卡内基梅隆大学材料研究部颁发，旨在研究软磁纳米复合材料的合成、结构和性能关系，这些材料有望应用于能量转换和数据存储。获得该奖项后，McHenry教授和Laughlin教授将进行以下研究：(1)进一步加深对纳米结晶动力学的理解，将其作为控制磁性微观结构的工具；(2)确定纳米复合材料的微观结构（包括磁场和畴结构引起的微观结构变化）与软磁性能的关系。研究将从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)纳米结晶动力学模型的改进；(b)模拟纳米晶化过程中的化学分配及其在晶间磁耦合温度依赖性中的作用；(c)显微结构观察和磁性测量，旨在阐明诱导磁各向异性的微观机制。这些基于铁-钴- m -硼-铜（其中金属可以是铌、锆或铪）的软磁纳米复合材料被称为HITPERM，有望应用于高温、高频感应器件和数据存储中的感应元件。电力电子元件的小型化必须考虑电感元件、频率响应（功率密度、损耗）和热管理等问题。在垂直记录介质上的热辅助写入需要高温/高感应磁底层和写入磁头以及旋转阀传感器中的低噪声软磁层。磁性纳米复合材料的发展将受益于对磁性纳米结构/性能关系的基本理解。科学互动包括乔治亚理工学院和国家强磁场实验室的强场纳米结晶实验以及国家材料研究所（日本筑波）的场离子显微镜研究活动。研究工作将与旨在教授研究方法和向本科生传达最新技术的教育举措相结合。研究人员目前在教授应用磁学和磁性材料的研究生课程。本课程大纲将进行修订，以便提供本科课程学分，作为本科课程磁性材料课程的一部分。课程内容将咨询当地两家企业希捷公司和Magnetics公司。这项工作与美国空军和美国国家航空航天局资助的开发高频、高温感应装置的努力相结合。

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.