US-Federal Republic of Germany Cooperative Research: Thermodynamics and Short-Range Order in Amorphous Rare Earth - Transition Metal Alloys

美德合作研究：非晶态稀土-过渡金属合金的热力学和短程有序

• 批准号: 8901211
• 负责人: Frances Hellman
• 金额: $ 1.14万
• 依托单位: University of California-San Diego
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-06-01 至 1992-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8901211&HistoricalAwards=false
• 关键词: US; Federal; Republic; Germany; Cooperative

This award supports Professor Frances Hellman, University of California at San Diego, for collaborative research with Dr. Ruediger Bormann of the Institute of Metal Physics, University of Goettingen, Federal Republic of Germany. They are interested in ferri-magnetic amorphous metal alloys derived from rare earth and transition metal elements. Thin films of these alloys possess a large, poorly-understood uni- axial magnetic anisotropy, which may be induced in the short-range order by the growth process. Certain thermodynamic functions control the stability of the amorphous phase relative to the crystalline phases of these thin films. These investigators will prepare thin film samples of several alloys, differing in composition or deposition temperature. They will make extensive thermodynamic measurements (in Germany), in conjunction with magnetic and structural characterization (in California), in order to compare the degree and type of short range order. Dr. Hellman's background is in thin film specific heat measurement and in preparation and magnetic and structural characterization of amorphous rare earth-transition metal alloys. Her German collaborators have unique and extensive experience in calculations of amorphous and crystalline phase free energies, based on measurements of certain thermodynamic properties of amorphous materials (including thin films.) They also have an ultra-high vacuum magnetron sputtering system, dedicated to preparation of high purity amorphous metallic alloys, especially those containing magnetic elements. The question of intermediate and short range order in amorphous magnetic materials and their relationship to the magnetic anisotropy is of basic as well as technological interest. The difficulty of making thermodynamic measurements in amorphous thin films has delayed progress in this area of materials science. This work should contribute to resolving the question of the origin of magnetic anisotropy in amorphous films. It will also help determine the conditions leading to phase separation in certain alloys which are promising magnetic storage materials.

该奖项支持加州大学弗朗西斯·赫尔曼教授 在圣地亚哥，与博士Ruediger鲍曼合作研究， 德国联邦哥廷根大学金属物理研究所 德国共和国 他们对亚铁磁性非晶态感兴趣 源自稀土和过渡金属元素的金属合金。 这些合金的薄膜具有一个大的，不太清楚的单位， 轴向磁各向异性，这可能是在短距离感应 按生长过程排序。 某些热力学函数 控制非晶相相对于 这些薄膜的结晶相。 这些调查人员将 制备几种不同成分合金的薄膜样品 或沉积温度。 他们将使广泛的热力学 测量（在德国），结合磁性和结构 表征（在加州），以比较程度和 短距离的命令。 赫尔曼博士的背景是电影 比热测量和制备中以及磁性和 稀土-过渡金属非晶态结构表征 合金. 她的德国合作者拥有独特而丰富的经验 在计算非晶和晶相自由能时，基于 非晶态合金某些热力学性质的测量 材料（包括薄膜）。 他们也有一个超高的 真空磁控溅射系统，专用于制备高性能的 纯非晶态金属合金，特别是含有 磁性元素 非晶态中短程有序问题 磁性材料及其与磁各向异性的关系 既有基础性的，也有技术性的。 的难度 在非晶薄膜中进行热力学测量已经推迟了 在材料科学领域取得的进展。 这项工作应 有助于解决磁起源问题 非晶薄膜的各向异性。 这也将有助于确定 在某些合金中导致相分离的条件， 很有前途的磁存储材料。