CAREER: A roadmap to atomically ordered complex materials via control of entropic mixing

职业：通过控制熵混合实现原子有序复杂材料的路线图

• 批准号: 2047251
• 负责人: Adam Hauser
• 金额: $ 52.39万
• 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: 2021
• 资助国家: 美国
• 起止时间: 2021-06-01 至 2026-05-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2047251&HistoricalAwards=false
• 关键词: CAREER; roadmap; atomically; ordered; complex

Non-Technical AbstractThe ability to atomically order crystalline materials is central to advancing technology. In the 1980s, 99% atomic ordering in two-element materials was developed, wherein two elements alternate nearly perfectly in their atomic site occupations. This enabled high-frequency transistors, which led to the cell phone revolution and high-efficiency solar panel technologies. Theoretical predictions tout revolutionary new material properties in complex (3+ elements) materials that will make possible new devices with broad application in information technology, solar cells, lighting, microwave communications, thermoelectrics, and power electronics. However, achieving the 99% atomic ordering required to realize those properties has remained elusive. The goal of this project is to systematically gain an understanding of the fundamental ordering mechanisms in complex materials. This research integrates computational theory and experimental results to create a set of criteria that can be used to design materials of sufficiently high atomic ordering (99%) to realize their intrinsic properties. This research directly integrates educational activities to impact underrepresented minorities, women, and underserved rural communities in STEM fields, and ensure that undergraduate education includes research experience. This mentor-based strategy focuses on elevating science, technology, engineering and mathematics (STEM) educators in underrepresented communities in rural Alabama and Mississippi. K-12 educators gain access to university faculty and specialists at the Alabama Science in Motion program to plan classes and laboratory sessions, and through the Alabama Math, Science and Technology Summer Institute receive training to qualify their rural school district for program/equipment funding. Undergraduate summer researchers are recruited from local Historically Black Colleges and Universities, minority-serving institutions and the American Physical Society’s Conferences for Undergraduate Women in Physics. Undergraduate students will also work as research assistants during each school year.Technical AbstractImperfect atomic ordering in complex materials is a pervasive issue in the condensed matter and materials communities: A model that accounts for entropic mixing disorder is required before complex materials can be applied widely. First principles calculations can accurately predict the intrinsic (structural, electronics, magnetic/magnetodynamic) material properties of an ordered system, but near-perfect (99%) atomic ordering is needed to manifest those properties. At present, it is a complex and computationally expensive task to determine if the system can form with the required atomic ordering in the presence of thermal and growth energies. The central hypothesis of this research is that high atomic ordering can be predicted by incorporating existing metallurgical metrics that indicate the level of entropic mixing. To test the hypothesis, computational predictions of ordering and properties are produced for a range of three-element L21-ordered Heusler alloys, chosen specifically due to decades-long frustration in realizing predictions of high spin polarization due to atomic disorder. Although applications often prefer highly ordered systems, materials with a range of ordering levels are selected to refine a robust quantitative model and provide a roadmap for material design. Thin films of each material system are grown with low energetics by the Sputter Beam Epitaxy method invented by the principal investigator, such that atomic ordering and material properties of each system can be compared to predictions with minimal extrinsic contribution. The results form a feedback loop between theory and experiment to establish and refine a quantitative model of atomic ordering when three or more elements are used. A quantitative predictive model for atomic ordering in complex alloys broadly translates to the many other fields whose material systems are plagued by entropic mixing.This project is jointly funded by the Electronic and Photonic Materials Program and the Established Program to Stimulate Competitive Research.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

非技术性摘要晶体材料原子有序化的能力是技术进步的核心。在20世纪80年代，开发了双元素材料中99%的原子有序性，其中两种元素在其原子位置占据中几乎完美地交替。这使得高频晶体管成为可能，导致了手机革命和高效太阳能电池板技术。理论预测吹捧复杂（3+元素）材料中革命性的新材料特性，这些特性将使新设备成为可能，在信息技术，太阳能电池，照明，微波通信，热电和电力电子学中具有广泛的应用。 然而，实现这些特性所需的99%原子有序化仍然是难以捉摸的。该项目的目标是系统地了解复杂材料中的基本有序机制。这项研究整合了计算理论和实验结果，创建了一套标准，可用于设计具有足够高原子有序度（99%）的材料，以实现其固有特性。这项研究直接整合了教育活动，以影响在STEM领域代表性不足的少数民族，妇女和服务不足的农村社区，并确保本科教育包括研究经验。这一以导师为基础的战略侧重于提升亚拉巴马和密西西比农村代表性不足社区的科学、技术、工程和数学（STEM）教育工作者。K-12教育工作者可以在亚拉巴马科学运动计划中接触大学教师和专家，以规划课程和实验室课程，并通过亚拉巴马数学，科学和技术暑期学院接受培训，以使其农村学区有资格获得计划/设备资金。本科夏季研究人员从当地历史上的黑人学院和大学，少数民族服务机构和美国物理学会的物理学本科妇女会议招募。本科生也将在每个学年担任研究助理。Technical AbstractImperfect Atomic Ordering in Complex Materials是凝聚态物质和材料界的一个普遍问题：在复杂材料可以广泛应用之前，需要一个考虑熵混合无序的模型。第一原理计算可以准确地预测有序系统的内在（结构，电子学，磁/磁动力学）材料特性，但需要接近完美（99%）的原子有序来表现这些特性。目前，它是一个复杂的和计算昂贵的任务，以确定系统是否可以形成所需的原子有序的热和生长能量的存在下。这项研究的中心假设是，高原子有序性可以通过结合现有的冶金度量，表明熵混合的水平进行预测。为了验证这一假设，计算预测的顺序和性能的范围内的三个元素的L21有序的Heusler合金，特别是选择由于几十年来的挫折，实现高自旋极化由于原子无序的预测。尽管应用程序通常更喜欢高度有序的系统，但选择具有一系列有序级别的材料来改进稳健的定量模型并为材料设计提供路线图。每种材料系统的薄膜都是通过主要研究者发明的溅射束外延方法以低能量生长的，这样每个系统的原子有序性和材料特性可以与具有最小外部贡献的预测进行比较。结果形成了理论和实验之间的反馈回路，以建立和完善原子有序的定量模型时，使用三个或更多的元素。复杂合金中原子有序的定量预测模型广泛地应用于许多其他领域，这些领域的材料系统受到熵混合的困扰。该项目由电子和光子材料计划和刺激竞争研究的既定计划共同资助。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响进行评估，被认为值得支持审查标准。

项目成果

Formation of Mn-rich interfacial phases in Co2FexMn1-xSi thin films

Co2FexMn1-xSi 薄膜中富锰界面相的形成

• DOI: 10.1016/j.jmmm.2024.171884
• 发表时间: 2024
• 期刊: Journal of Magnetism and Magnetic Materials
• 影响因子: 2.7
• 作者: Ming Law, Ka;Thind, Arashdeep S.;Pendharkar, Mihir;Patel, Sahil J.;Phillips, Joshua J.;Palmstrom, Chris J.;Gazquez, Jaume;Borisevich, Albina;Mishra, Rohan;Hauser, Adam J.
• 通讯作者: Hauser, Adam J.

Ultralow effective Gilbert damping and induced orbital moment in strain-engineered FeGe films with Curie temperature exceeding room temperature

居里温度超过室温的应变工程 FeGe 薄膜中的超低有效吉尔伯特阻尼和诱导轨道矩

• DOI: 10.1016/j.jmmm.2022.170053
• 发表时间: 2022
• 期刊: Journal of Magnetism and Magnetic Materials
• 影响因子: 2.7
• 作者: Budhathoki, Sujan;Sapkota, Arjun;Law, Ka Ming;Ranjit, Smriti;Stephen, Gregory M.;Heiman, Don;Jamer, Michelle E.;Mewes, Tim;Hauser, Adam J.
• 通讯作者: Hauser, Adam J.

Phase and d-d hybridization control via electron count for material property control in the X2FeAl material class

• DOI: 10.1016/j.jmmm.2024.171932
• 发表时间: 2024-03
• 期刊: Journal of Magnetism and Magnetic Materials
• 影响因子: 2.7
• 作者: K. Law;Ridwan Nahar;Riley Nold;Michael Zengel;Justin Lewis;Adam J. Hauser