Exchange Bias of Ideal Antiferromagnetic Thin Films

理想反铁磁薄膜的交换偏置

• 批准号: 0400578
• 负责人: David Lederman
• 金额: $ 33万
• 依托单位: West Virginia University Research Corporation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-04-01 至 2008-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0400578&HistoricalAwards=false
• 关键词: Exchange; Bias; Ideal; Antiferromagnetic; Thin

The proposed research will focus on the study of exchange bias, a phenomenon resulting from the interface magnetic interactions between ferromagnetic and antiferromagnetic materials. Recent studies have established that the amount of interface disorder, defects in the antiferromagnet, the stoichiometry of the interface layer, and magnetic anisotropy energies influence the exchange bias, but the relative importance of these factors is not well understood. The main scientific objective of this proposal is to understand the effect of these parameters in well-characterized, ideal antiferromagnetic insulators, in order to eventually apply some of the ideas gleaned from these measurements to more complex antiferromagnets. Because the experiments will be carried out on relatively simple magnetic systems, the results will provide experimental data that could be explained using first principle models and simulated with a computer. In addition to the usual involvement of undergraduate and graduate students and postdocs, in the day-to-day research, there are three important educational activities associated with the proposed work: 1) involvement with science programs in middle schools in rural West Virginia; 2) development of interactive teaching tools for beginning physics lecture classes, and 3) development of new teaching materials for advanced laboratory. This program will have a significant impact on education from the 7-16 level and beyond, emphasizing science education for disadvantaged students in rural schools in West Virginia. This is especially important for the state of West Virginia, whose economy has traditionally relied on manufacturing and coal production, but where high-technology industry is increasingly playing an important role. Ferromagnetic materials are the basis of modern data storage devices, including computer hard disk drives. Modern magnetic sensors and proposed magnetic memory devices also rely on antiferromagnetic materials that can prevent ferromagnetic thin films from changing their magnetic properties when an external magnetic field is applied. The mechanism whereby this ferromagnetic-antiferromagnetic interaction occurs, called exchange bias, is not well understood. One of the problems is that many antiferromagnetic materials have very complex magnetic configurations which make the scientific data difficult to analyze. The main scientific objective of this proposal is to understand the effect by using well-characterized, ideal antiferromagnetic thin film materials whose properties are relatively simple and well understood. Because of the simplicity of these materials, the results will provide experimental data that could be explained using first principle models and simulated with a computer. The ideas gleaned from these studies will be applied to the more complex antiferromagnets used in magnetic electronic devices. The long-term result will be magnetic electronic devices with increased storage capacity, lower power consumption, and increased speed. In addition to the usual involvement of undergraduate and graduate students and postdocs, in the day-to-day research, there are three important educational activities associated with the proposed work: 1) involvement with science programs in middle schools in rural West Virginia; 2) development of interactive teaching tools for beginning physics lecture classes, and 3) development of new teaching materials for advanced laboratory. This program will have a significant impact on education from the 7-16 level and beyond, emphasizing science education for disadvantaged students in rural schools in West Virginia. This is especially important for the state of West Virginia, whose economy has traditionally relied on manufacturing and coal production, but where high-technology industry is increasingly playing an important role.

拟议的研究将集中于交换偏差的研究，这是由铁磁和抗铁磁材料之间的界面磁相互作用引起的现象。 最近的研究表明，界面障碍的量，抗铁磁铁的缺陷，界面层的化学计量和磁各向异性能量会影响交换偏见，但是这些因素的相对重要性尚不清楚。 该提案的主要科学目标是了解这些参数在特征良好的，理想的抗铁磁绝缘子中的效果，以最终将这些测量结果收集的一些想法应用于更复杂的反铁磁体。 由于实验将在相对简单的磁系统上进行，因此结果将提供实验数据，可以使用第一原理模型来解释，并使用计算机进行模拟。 除了在日常研究中，本科生和研究生和博士后的通常参与外，还与拟议的工作相关的三项重要教育活动：1）参与西弗吉尼亚州农村中学的科学课程； 2）开发用于开始物理讲座课程的交互式教学工具，以及3）开发高级实验室的新教学材料。 该计划将对从7-16层及以后的教育产生重大影响，强调西弗吉尼亚州农村学校的弱势学生科学教育。 这对于西弗吉尼亚州尤其重要，西弗吉尼亚州传统上依靠制造业和煤炭生产，但是高科技行业越来越多地发挥重要作用。铁磁材料是现代数据存储设备的基础，包括计算机硬盘驱动器。 现代磁性传感器和提议的磁性记忆设备还依赖于抗铁磁材料，在应用外部磁场时，可以防止铁磁薄膜更改其磁性。 这种铁磁 - 抗铁磁相互作用发生的机制被称为交换偏见，尚不清楚。 问题之一是，许多抗铁磁材料具有非常复杂的磁性构型，这使得科学数据难以分析。 该提案的主要科学目标是通过使用良好的，理想的反铁磁薄膜材料来理解效果，其特性相对简单且知名度很好。 由于这些材料的简单性，结果将提供实验数据，可以使用第一原理模型来解释，并使用计算机进行模拟。 这些研究收集的想法将应用于磁性电子设备中使用的更复杂的抗fiferromagnets。 长期的结果将是磁性电子设备，其存储容量增加，功耗降低和速度提高。 除了在日常研究中，本科生和研究生和博士后的通常参与外，还与拟议的工作相关的三项重要教育活动：1）参与西弗吉尼亚州农村中学的科学课程； 2）开发用于开始物理讲座课程的交互式教学工具，以及3）开发高级实验室的新教学材料。 该计划将对从7-16层及以后的教育产生重大影响，强调西弗吉尼亚州农村学校的弱势学生科学教育。 这对于西弗吉尼亚州尤其重要，西弗吉尼亚州传统上依靠制造业和煤炭生产，但是高科技行业越来越多地发挥重要作用。