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：随着对开发纳米级设备的需求不断增加，“缩放”金属层中存在一些重大挑战，同时保持其原子级稳定性。这是磁性存储行业特别感兴趣的，它需要新材料来达到每平方英寸范围内的超高存储密度。高磁晶的各向异性合金FEPT，COPT，FEPD和MNAL是下一代磁性数据存储系统的候选金属间化合物。当这些金属被溅射为纳米粒子微观结构时，它们采用了一个可稳态的相，需要高温退火以形成适当的化学有序相。应力可以对纳米级的相位和微观结构产生重大影响。纳米级缺乏足够的原子微观结构表征，使这种阶段转换尚未得到充分理解。研究将提供残留应力对纳米级方向上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耦合，以解决膜应力对订购，组成分离和膜增长的早期阶段的影响。通过将膜的残余应力状态与其微观结构和有序的相位演变相关联，将实现金属间稳定性关系。非技术：结果将对磁信息存储的实际方面产生重大影响。这项研究将平衡大学和科学界的教学，奖学金和服务。将开发一项针对专业发展和招募研究生，本科生和高中生材料科学和工程学的协同计划。它将包括高中夏季的研究经验，以及历史悠久的黑人大学（HBCU）的教师的教学科学。 HBCU教师的夏季研究将纳入研究中。研究将通过由阿拉巴马大学信息技术中心（MINT）协调的研讨会传播到磁性工业。