RII Track--4: Controlling Point-Defect Energetics in Complex Oxides Via Interfacial Strain

RII Track--4：通过界面应变控制复杂氧化物中的点缺陷能量

• 批准号: 2245128
• 负责人: Dilpuneet Aidhy
• 金额: $ 20.29万
• 依托单位: Clemson University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-10-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2245128&HistoricalAwards=false
• 关键词: RII; Track; Controlling; Point; Defect

What silicon was to the 20th century, quantum materials are to the 21st. A million times faster computers than today's most powerful supercomputers, or, electricity transported across the national grid at no loss, is the sort of future that will be realized by the power of quantum materials. Realizing this vision requires developing new materials and understanding key materials features that give rise to such incredible properties. Interfacial oxide materials, i.e., those formed by joining of two different oxide materials, are one of such promising materials. An example of an interfacial oxide material is an interface between LaNiO3 and SrTiO3. Because these two materials have different distances between their atoms, when joined to form an interface, their atomic bonds are strained that can lead to creation of defects, i.e., loss of specific oxygen atoms. Creation of these defects has been proposed to be a key underlying reason of such exciting properties. In this project, we focus on understanding the critical correlation between strain and oxygen defects such that the defects could be controlled, at will. This work will advance Wyoming's vision of computational sciences, develop basic understanding of designing quantum materials, and contribute to "The Quantum Leap: Leading the Next Quantum Revolution" which is one of the next ten big NSF ideas.The interface structure formed by joining two different complex oxides (chemical formula ABO3) contains an interfacial strain which leads to formation of oxygen vacancies at the interface. These vacancies are considered to be one of key reasons inducing many novel electronic properties. The overarching goal of the proposal is to develop a fundamental understanding of the correlation between interfacial strain and oxygen vacancies in LaNiO3 grown on SrTiO3. This correlation will allow control over the stability (i.e., location and concentration) of vacancies via strain, at will. In-situ X-ray Photon Correlation Spectroscopy (XPCS) experiments at Advanced Photon Source (APS) in Argonne National Laboratory and density functional theory calculations will be used to elucidate the thermodynamics and kinetics of phase transitions in LaNiOx phases, which appears to be induced via the ordering and disordering of the oxygen vacancies. This understanding will advance the science of gaining control over the metal-insulator transition temperature in LaNiO3.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.

就像硅之于 20 世纪一样，量子材料之于 21 世纪。比当今最强大的超级计算机快一百万倍的计算机，或者通过国家电网无损耗传输电力，都是量子材料的力量将实现的未来。实现这一愿景需要开发新材料并了解产生如此令人难以置信的特性的关键材料特性。界面氧化物材料，即通过连接两种不同氧化物材料形成的材料，是此类有前途的材料之一。界面氧化物材料的一个例子是LaNiO 3 和SrTiO 3 之间的界面。由于这两种材料的原子之间的距离不同，因此当连接形成界面时，它们的原子键会受到拉紧，从而导致缺陷的产生，即特定氧原子的损失。这些缺陷的产生被认为是这些令人兴奋的特性的关键根本原因。在这个项目中，我们专注于了解应变和氧缺陷之间的关键相关性，以便可以随意控制缺陷。这项工作将推进怀俄明州的计算科学愿景，发展对设计量子材料的基本理解，并为“量子飞跃：引领下一次量子革命”做出贡献，这是接下来的十大 NSF 想法之一。通过连接两个形成的界面结构不同的复合氧化物（化学式ABO3）含有界面应变，导致界面处形成氧空位。这些空位被认为是引发许多新颖电子特性的关键原因之一。该提案的总体目标是对 SrTiO3 上生长的 LaNiO3 中的界面应变和氧空位之间的相关性有一个基本的了解。这种相关性将允许通过应变随意控制空位的稳定性（即位置和浓度）。阿贡国家实验室先进光子源 (APS) 的原位 X 射线光子相关光谱 (XPCS) 实验和密度泛函理论计算将用于阐明 LaNiOx 相中相变的热力学和动力学，这似乎是诱导的通过氧空位的有序和无序。这种理解将推进控制 LaNiO3 金属-绝缘体转变温度的科学。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审查标准进行评估，被认为值得支持。