DMREF: Collaborative Research: Emergent Functionalities in 3d/5d Multinary Chalcogenides and Oxides

DMREF：协作研究：3d/5d 多元硫属化物和氧化物中的新兴功能

• 批准号: 1629079
• 负责人: Janice Musfeldt
• 金额: $ 33万
• 依托单位: University of Tennessee Knoxville
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-01 至 2022-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1629079&HistoricalAwards=false
• 关键词: DMREF; Collaborative; Research; Emergent; Functionalities

Non-technical abstractThis research program is focused on understanding and enlarging the class of materials in which atoms from the bottom rows of the periodic table play an important role. Crystalline compounds containing these elements have an interrelated set of properties including strong coupling between electron motion and spin, unusual magnetic behavior, broader electronic energy bands, and a tendency to pairwise attraction of neighboring atoms. Special attention is given to the exploration of layered materials that include tellurium, as these show a wide variety of structural motifs. First-principles computational methods are used to investigate candidate materials of this class, identifying those that appear most promising as targets for directed synthesis and in-depth experimental study. Comparisons between theory and experiment provide feedback to refocus the theoretical and computational effort. The team provides capabilities in bulk and thin-film materials growth coupled to characterization using optical, scattering, and scanning-probe techniques. The activity provides educational opportunities through the involvement of undergraduates in research, the coordination with outreach programs at the Liberty Science Center in New Jersey, and the organization of topical workshops and conferences.Technical AbstractInterest in 5d materials and 3d/5d hybrids has blossomed in recent years in response to scientific advances and applications in the areas of hard magnets, topological insulators, multiferroics, superconductors, and thermoelectrics. These materials are unique for several reasons. First, strong spin-orbit coupling competes with magnetic, crystal-field, many-body Coulomb, and other interactions in such a way as to drive new physical behaviors, such as the effective spin 1/2 state that emerges in certain iridates. Second, the bonding interactions associated with the larger size of the 5d orbitals promotes inter-cation dimerization in pairwise, chain-like, and other complex orderings. Third, the relativistic shifts in orbital energies, combined with spin-orbit coupling and bandwidth effects, can drive band inversions leading to topological phases and enhanced Rashba splittings. In 3d/5d hybrid materials, the interplay of these properties with the strong magnetic moments and correlation effects associate with the3d ions provides greater chemical flexibility and functional richness. The goal of the present project is to improve the understanding of how spin-orbit coupling enhances functionality in compounds containing 3d and 5d ions, and clarify how properties depend on control parameters such as spin-orbit strength, d-shell filling, dimensionality, and structural distortions. Specifically, the activity consists of a concerted theoretical and experimental exploration of materials in which 3d and 5d transition-metal sites coexist in multicomponent chalcogenide and oxide crystals and films. The unique physical and chemical properties of these materials provide a platform for a materials discovery paradigm in which first-principles computational methods are used to investigate candidate materials, identifying those that appear most promising as targets for directed synthesis and in-depth experimental study. Target materials systems include under-explored binary 5d tellurides, ternary 3d-5d tellurides and selenides, 3d-5d chalcogenide superlattices, and 3d-5d hexagonal chain compounds. The research also targets the synthesis of new materials and nanostructures for topological states including quantum anomalous Hall, strong topological insulator, and Weyl semimetal phases.The methods used in the research are diverse. Comparison between theory and experiment provides feedback to refocus the theoretical and computational effort, which is carried out using first-principles methods including density-functional theory and dynamical mean-field theory. The team provides capabilities in both bulk and thin-film (molecular beam epitaxy and pulsed-laser deposition) growth, while the understanding and optimization of the unique materials properties is facilitated using X-ray, optical, scanning tunneling, transport, and neutron scattering techniques.

非技术抽象研究计划的重点是理解和扩大材料类别的材料类别，在这些材料中，元素周期表底部的原子起着重要作用。 包含这些元素的结晶化合物具有相互关联的特性集，包括电子运动和自旋之间的强耦合，异常的磁性行为，更广泛的电子能带，以及相邻原子成对吸引的趋势。特别注意包括柜子在内的分层材料的探索，因为这些材料显示了各种各样的结构基序。第一原理计算方法用于研究该类别的候选材料，从而确定那些似乎最有前途的是定向合成和深入实验研究的目标。理论与实验之间的比较提供了反馈，以重新集中理论和计算工作。该团队提供了散装和薄膜材料的能力，并使用光学，散射和扫描探针技术进行表征，并提供表征。这项活动通过在新泽西州自由科学中心与外展计划的协调以及组织和会议组织的组织来提供教育机会。近年来，在近年来，在近年来，杂种者的应用程序，杂种，杂物，远程杂货店的杂物，杂种，远程杂货店的杂货店，杂物，杂物，杂物，杂物，杂物，杂物，杂物，杂物，杂物，杂物，杂物，杂物，杂物，杂物，杂种，杂物，杂物，杂种，杂物，杂物，杂乱无章的技术抽象感兴趣的组织组织。超导体和热电学。这些材料是独一无二的。首先，强的自旋轨道耦合与磁性，晶体场，多体库仑和其他相互作用竞争，以驱动新的物理行为，例如在某些虹彩中出现的有效自旋1/2状态。 其次，与5D轨道较大尺寸相关的粘结相互作用促进了成对，链样和其他复杂顺序中的隔离二聚化。 第三，轨道能中的相对论变化，再加上自旋轨道耦合和带宽效应，可以驱动带的带子反转，从而导致拓扑阶段和增强的RashBA分布。在3D/5D杂交材料中，这些特性与强磁矩和与该3D离子相关的相关效应的相互作用提供了更大的化学柔韧性和功能丰富度。本项目的目的是提高对自旋轨道耦合如何增强包含3D和5D离子化合物的功能的理解，并阐明属性如何依赖于控制参数，例如旋转轨道强度，D壳填充，维度和结构扭曲。具体而言，该活性由一致的理论和实验探索材料组成，其中3D和5D过渡金属位点在多组分硫代基因并氧化物晶体以及氧化物晶体和膜中共存。这些材料的独特物理和化学特性为材料发现范式提供了一个平台，其中使用第一原理计算方法来研究候选材料，从而确定那些看起来最有前途的材料是有向综合和深入实验研究的目标。目标材料系统包括爆炸不足的二进制5D泰氏尿苷，三元3D-5D泰氏尿素和硒化体，3D-5D粉红色的超级晶格以及3D-5D六边形链链链化合物。该研究还针对拓扑状态的新材料和纳米结构的合成，包括量子异常大厅，强拓扑绝缘子和Weyl半准阶段。研究中使用的方法多样。理论与实验之间的比较提供了反馈，以重新集中理论和计算工作，这是使用第一原理方法进行的，包括密度功能理论和动态均值场理论。 该团队在散装和薄膜（分子束外延和脉冲激光沉积）的生长中提供功能，同时使用X射线，光学，扫描隧道，传输，传输和中子散射技术来促进对独特材料特性的理解和优化。

项目成果

Band-Mott mixing hybridizes the gap in Fe2Mo3O8

• DOI: 10.1103/physrevb.104.195143
• 发表时间: 2021-11
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: K. Park;G. Pascut;G. Khanal;M. Yokosuk;Xianghan Xu;B. Gao;M. Gutmann;A. Litvinchuk;V. Kiryukhin;S. Cheong;D. Vanderbilt;K. Haule;J. Musfeldt