CAREER: Microstructure and Mean Stress Evolution in Atomistic Ordering Thin Films

职业：原子有序薄膜中的微观结构和平均应力演化

• 批准号: 0547445
• 负责人: Gregory Thompson
• 金额: $ 49.72万
• 依托单位: University of Alabama Tuscaloosa
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-08-15 至 2012-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0547445&HistoricalAwards=false
• 关键词: CAREER; Microstructure; Mean; Stress; Evolution

TECHNICAL: With an ever-increasing demand for developing nanoscale devices, several significant challenges exist in 'scaling-down' intermetallics while maintaining their atomic-order stability. This is of particular interest to the magnetic storage industry, which needs new materials to achieve ultra-high storage density in the terabit per square-inch range. High magnetocrystalline anisotropy alloys FePt, CoPt, FePd and MnAl are candidate intermetallic compounds for the next-generation of magnetic data storage systems. When these metals are sputtered deposited as a nanogranular microstructure, they adopt a metastable phase requiring a high temperature anneal to form the appropriate chemically ordered phase. Stress can have a significant influence on the phase and microstructure at the nanoscale. The lack of sufficient atomistic microstructural characterization at the nanoscale has made this phase transformation not well understood. Research will provide the influence of residual stress on the nucleation and structural stability of ordered alloys in the nanometer regime. Atom Probe Tomography (APT), high-resolution transmission electron microscopy, and in-situ thin film stress monitoring will be coupled to address the effect of film stress on the early stages of ordering, composition segregation, and film growth. By correlating the residual stress state of a film to its microstructure and ordered phase evolution, the intermetallic stability relationship to size will be realized. NON-TECHNICAL: Results will have a major impact on the practical aspects of magnetic information storage. The research will balance teaching, scholarship, and service to the university and the scientific community. A synergistic program for the professional development and recruitment of graduate, undergraduate, and high school students into materials science and engineering will be developed. It will include a high school summer research experience, and teaching materials science to faculty from historically black colleges and universities (HBCU). A summer research sabbatical for HBCU faculty will be incorporated into the research. Research will be disseminated to the magnetic industry through workshops coordinated by the Center for Materials for Information Technology (MINT) at University of Alabama.

技术：随着开发纳米级器件的需求不断增加，在“按比例缩小”金属间化合物同时保持其原子级稳定性方面存在一些重大挑战。这对于磁存储行业尤其重要，该行业需要新材料来实现太比特/平方英寸范围内的超高存储密度。高磁晶各向异性合金 FePt、CoPt、FePd 和 MnAl 是下一代磁数据存储系统的候选金属间化合物。当这些金属被溅射沉积为纳米颗粒微观结构时，它们采用亚稳态相，需要高温退火才能形成适当的化学有序相。应力会对纳米尺度的相和微观结构产生重大影响。由于缺乏足够的纳米尺度原子微观结构表征，使得这种相变尚未得到很好的理解。研究将提供残余应力对纳米级有序合金的成核和结构稳定性的影响。原子探针断层扫描（APT）、高分辨率透射电子显微镜和原位薄膜应力监测将结合起来，以解决薄膜应力对有序、成分偏析和薄膜生长早期阶段的影响。通过将薄膜的残余应力状态与其微观结构和有序相演化相关联，将实现金属间稳定性与尺寸的关系。非技术性：结果将对磁信息存储的实际方面产生重大影响。该研究将平衡教学、学术以及对大学和科学界的服务。将制定材料科学与工程专业发展和招收研究生、本科生和高中生的协同计划。它将包括高中暑期研究经验，以及向历史悠久的黑人学院和大学 (HBCU) 的教师教授材料科学。 HBCU 教师的暑期研究休假将纳入该研究。研究成果将通过阿拉巴马大学信息技术材料中心 (MINT) 协调的研讨会传播到磁性行业。