Influence of Defects on Magnetic Hysteresis: A Synthesis of Electronic Structure Theory and Micromagnetics

缺陷对磁滞的影响：电子结构理论与微磁学的综合

• 批准号: 9971573
• 负责人: Randall Victora
• 金额: $ 30万
• 依托单位: University of Minnesota-Twin Cities
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-07-15 至 2003-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9971573&HistoricalAwards=false
• 关键词: Influence; Defects; Magnetic; Hysteresis; Synthesis

9971573VictoraThis award supports research and education in the magnetic properties of materials and involves a collaborative effort between Tulane University and the University of Minnesota. The research seeks to develop simulation techniques to describe macroscopic magnetic properties, such as hysteresis loops, of materials where these are influenced by atomic-scale defects. In films of thickness 5-50 nm, the influence of defects in nucleating domains or pinning domain walls prevents ordinary micromagnetic simulations from achieving quantitative accuracy without introducing adjustable parameters. Technologically important materials,e.g. magnetic recording media and permanent magnets, exhibit behavior that is strongly defect driven. With increasing storage density, the resistance of the material to exhibiting superparamagentism depends on the interaction between thermal fluctuations and defects. To enable the reliable simulation of the magnetic properties of these materials, the PIs will use simulation techniques that include thermal fluctuations and information on defects (local exchange and anisotropy) obtained from electronic structure calculations. This award supports a research effort that addresses fundamental problems as well as problems of interest to magnetic recording and data storage industries. It is a collaborative effort between the University of Minnesota and Tulane University. The PIs seek to develop methods to include information from atomic-scale calculations in computer simulations of large-scale magnetic properties of materials for which defects play an important role. The research contributes to the training of students in electronic structure and simulation techniques.

9971573 Victora该奖项支持材料磁性的研究和教育，并涉及杜兰大学和明尼苏达大学之间的合作努力。 该研究旨在开发模拟技术来描述宏观磁特性，如磁滞回线，这些材料的原子级缺陷的影响。 在厚度为5-50 nm的膜中，成核畴或钉扎畴壁中的缺陷的影响阻止普通的微磁模拟在不引入可调节参数的情况下实现定量准确性。 技术上重要的材料，例如磁记录介质和永磁体，表现出强烈缺陷驱动的行为。 随着存储密度的增加，材料表现出超顺磁性的阻力取决于热波动和缺陷之间的相互作用。 为了能够可靠地模拟这些材料的磁性，PI将使用模拟技术，包括热波动和从电子结构计算中获得的缺陷信息（局部交换和各向异性）。该奖项支持解决基本问题以及磁记录和数据存储行业感兴趣的问题的研究工作。 这是明尼苏达大学和杜兰大学之间的合作努力。 PI寻求开发方法，将来自原子尺度计算的信息包括在缺陷发挥重要作用的材料的大尺度磁性的计算机模拟中。 该研究有助于电子结构与仿真技术的培养。