CAREER: Confining Magnetism to Two-Dimensions in Transition Metal Oxide Atomic Layers

职业：将磁性限制在过渡金属氧化物原子层的二维范围内

• 批准号: 1751455
• 负责人: Divine Kumah
• 金额: $ 58.95万
• 依托单位: North Carolina State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-07-01 至 2023-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1751455&HistoricalAwards=false
• 关键词: CAREER; Confining; Magnetism; Two; Dimensions

NON-TECHNICAL DESCRIPTION: As the dimensions of materials in modern devices approach thicknesses close to a few atomic layers, small deviations in atomic arrangements can occur leading to electronic and magnetic properties which differ vastly from the properties of the bulk materials. Using advanced synthesis tools which permit the combination of atomic layers of materials with different compositions, the atomic deviations can be effectively manipulated to produce novel effects. In this project, high-intensity X-rays are used to image the atomic-scale structure of the interfaces of layers of thin crystalline oxide films. The information gained from imaging these materials is required to help scientists and engineers understand why some oxide materials lose their useful magnetic properties when their thicknesses are reduced to a few atomic layers. The X-ray results are combined with high-resolution electron microscopy, magnetic and transport measurements, and theoretical calculations to design specific combinations of oxide materials to achieve magnetism in single layers of oxide materials. This project has exciting implications for the design of novel materials and devices for information processing, quantum computing and low-powered sensors. This project provides a highly collaborative environment and access to advanced technical resources for training undergraduate and graduate students in the development of the next generation of advanced nanoscale materials. The project provides low-cost tools for visualizing abstract concepts related to crystallography to foster the public understanding of the development of new technologically-relevant crystalline materials.TECHNICAL DETAILS: This project uses state-of-the-art synchrotron X-ray facilities at the Argonne National Laboratory and the Berkeley National Laboratory to carry out three-dimensional non-destructive atomic-scale mapping of the atomic, electronic and magnetic structures of magnetic perovskite oxide surfaces and interfaces. This research provides a comprehensive understanding of the fundamental interactions which occur at the interfaces between atomically-thin magnetic oxide films and other polar and non-polar perovskite materials and establishes a link between the observed interactions and the physical properties of these systems. A combination of first principles theory, high-resolution electron microscopy and temperature-dependent magnetic, transport and element-specific synchrotron X-ray magnetic dichroism measurements is used to design novel oxide heterointerfaces for achieving the confinement of ferromagnetism in two-dimensional oxide layers. These materials have applications in novel spin-based electronic devices. The wide range of cutting-edge research tools utilized in this activity are used to enhance the education of undergraduate and graduate students to prepare them for careers in scientific research and materials and device engineering. An important component of this project is the development of low-cost augmented reality tools for visualizing complex atomic and electronic structures for classroom instruction and public outreach to K-12 schools.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.

非技术描述：随着现代设备中材料的尺寸接近接近几个原子层的厚度，原子排列的小偏差可能会导致电子和磁性特性，这与大量材料的性质大不相同。使用允许原子层与不同组成的原子层组合的高级合成工具，可以有效地操纵原子偏差以产生新的效果。在这个项目中，高强度X射线用于成像薄晶氧化物膜层的界面的原子尺度结构。从成像中获得的信息需要这些材料来帮助科学家和工程师理解为什么某些氧化物材料将其厚度降低到几个原子层时会失去其有用的磁性。 X射线结果与高分辨率电子显微镜，磁性和传输测量结果以及为设计氧化物材料的特定组合以实现氧化物材料单层的磁化而结合使用。该项目对信息处理，量子计算和低功率传感器的新型材料和设备的设计具有令人兴奋的含义。该项目为培训下一代高级纳米级材料的培训本科生和研究生提供了高度协作的环境和高级技术资源的访问。 The project provides low-cost tools for visualizing abstract concepts related to crystallography to foster the public understanding of the development of new technologically-relevant crystalline materials.TECHNICAL DETAILS: This project uses state-of-the-art synchrotron X-ray facilities at the Argonne National Laboratory and the Berkeley National Laboratory to carry out three-dimensional non-destructive atomic-scale mapping of the atomic, electronic and magnetic structures of magnetic钙钛矿氧化物表面和界面。这项研究提供了对原子上磁氧化物膜与其他极性和非极性钙钛矿材料之间界面上发生的基本相互作用的全面理解，并在观察到的相互作用与这些系统的物理特性之间建立了联系。第一原理理论，高分辨率电子显微镜和温度依赖性磁，传输和元素特异性同步加速器X射线磁性二色性测量的组合用于设计新型的氧化氧化物异源空间，以实现二维氧化物层中铁磁性的限制。这些材料在新型的基于自旋的电子设备中应用。在此活动中使用的各种尖端研究工具用于增强本科生和研究生的教育，以便为科学研究，材料和设备工程领域的职业做好准备。该项目的一个重要组成部分是开发低成本的增强现实工具，用于可视化复杂的原子和电子结构，用于课堂教学，并向K-12学校进行公共宣传。这项奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子优点和更广泛影响的审查标准来通过评估来支持的。

项目成果

Effect of strain on magnetic and orbital ordering of LaSrCrO3/LaSrMnO3 heterostructures

• DOI: 10.1103/physrevb.101.064420
• 发表时间: 2020-02-19
• 期刊: PHYSICAL REVIEW B
• 影响因子: 3.7
• 作者: Koohfar, Sanaz;Georgescu, Alexandru B.;Kumah, Divine P.
• 通讯作者: Kumah, Divine P.

Tuning of spin-orbit coupling in metal-free conjugated polymers by structural conformation

• DOI: 10.1103/physrevmaterials.4.085603
• 发表时间: 2020-08-28
• 期刊: PHYSICAL REVIEW MATERIALS
• 影响因子: 3.4
• 作者: Vetter, Eric;VonWald, Ian;Sun, Dali
• 通讯作者: Sun, Dali

Oxygen Vacancy-Induced Anomalous Hall Effect in a Nominally Non-magnetic Oxide

• DOI: 10.1007/s11664-022-09941-9
• 发表时间: 2022-09-24
• 期刊: JOURNAL OF ELECTRONIC MATERIALS
• 影响因子: 2.1
• 作者: Al-Tawhid, Athby H.;Kanter, Jesse;Ahadi, Kaveh
• 通讯作者: Ahadi, Kaveh

Superconductivity and Weak Anti-localization at KTaO3 (111) Interfaces

• DOI: 10.1007/s11664-022-09844-9
• 发表时间: 2022-08-19
• 期刊: JOURNAL OF ELECTRONIC MATERIALS
• 影响因子: 2.1
• 作者: Al-Tawhid, Athby H.;Kanter, Jesse;Ahadi, Kaveh
• 通讯作者: Ahadi, Kaveh

Exchange bias in La 0.7 Sr 0.3 CrO 3 /La 0.7 Sr 0.3 MnO 3 /La 0.7 Sr 0.3 CrO 3 heterostructures

La 0.7 Sr 0.3 CrO 3 /La 0.7 Sr 0.3 MnO 3 /La 0.7 Sr 0.3 CrO 3 异质结构中的交换偏向

• DOI: 10.1063/1.5130453
• 发表时间: 2020
• 期刊: AIP Advances
• 影响因子: 1.6
• 作者: Olmos, Rubyann;Iturriaga, Hector;Blazer, Dawn S.;Koohfar, Sanaz;Gandha, Kinjal;Nlebedim, Ikenna C.;Kumah, Divine P.;Singamaneni, Srinivasa R.
• 通讯作者: Singamaneni, Srinivasa R.