Neutron and X-Ray Scattering Studies of Transition-Metal Compounds with Large Spin-Orbit Coupling

具有大自旋轨道耦合的过渡金属化合物的中子和 X 射线散射研究

• 批准号: 1609935
• 负责人: Valery Kiryukhin
• 金额: $ 39.76万
• 依托单位: Rutgers University New Brunswick
• 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 2020-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1609935&HistoricalAwards=false
• 关键词: Neutron; Ray; Scattering; Studies; Transition

Nontechnical abstract:Compounds containing elements with large atomic numbers (such as iridium and osmium) exhibit a strong interaction between their magnetic and structural properties called spin-orbit coupling. It gives rise to exotic and technologically relevant properties, potentially useful for making superconductors, novel magnetic materials for low-power electronics, and permanent magnets. Herein, studies of two important classes of such compounds, the so-called transition-metal dichalcogenides and hexagonal chain oxide magnets, using x-ray and neutron probes are proposed. The obtained atomic-level crystallographic and magnetic structures of these compounds, as well as their dynamical properties, are expected to reveal the specifics of the action of the spin-orbit coupling in these materials. The resulting insights might help in the design of future high-performance permanent magnets, as well as novel nanoscale electronic devices.Technical abstract:Interaction of electronic degrees of freedom with crystal lattice gives rise to a plethora of interesting effects in transition-metal compounds, such as multiferroicity, and colossal magnetoresistance. Spin-orbit coupling (SOC) is an important magnetostructural coupling mechanism. In systems with electrons in 3d and 4d shells, SOC is usually weak. In 5d materials, however, it can qualitatively change the basic materials properties, leading to novel physical effects and new device concepts. Herein, x-ray and neutron scattering studies of the lattice and magnetic structures, as well as their dynamical properties, are proposed for two classes of 5d compounds. (1) Layered transition-metal dichalcogenides. The proposed studies include investigations of global and local lattice symmetry, long-range and local dimer orderings, and their role in destruction/promotion of exotic superconductivity, magnetic order, and spin-polarized electronic bands. (2) Quasi-one-dimensional hexagonal magnets exhibiting colossal magnetic coercivity, and unusual magnetic anisotropies. Studies of field-induced transitions, microscopic magnetic interactions, and magnetic domains are proposed. The goals include understanding the unusual magnetism in these compounds, its relationship to the physics of 5d electrons, and whether this physics could give an insight into functioning of permanent magnets.

含有大原子序数元素（如铱和锇）的化合物在它们的磁性和结构性质之间表现出强烈的相互作用，称为自旋轨道耦合。它产生了奇异的和技术相关的特性，可能用于制造超导体，低功率电子产品的新型磁性材料和永磁体。在这里，研究两个重要的类这样的化合物，所谓的过渡金属dichalcogenides和六方链氧化物磁铁，使用X射线和中子探针提出。所获得的这些化合物的原子级晶体学和磁性结构，以及它们的动力学性质，预计将揭示这些材料中自旋轨道耦合作用的细节。由此产生的见解可能有助于设计未来的高性能永磁体，以及新颖的纳米电子器件。技术摘要：电子自由度与晶格的相互作用在过渡金属化合物中产生了大量有趣的效应，如多铁性和巨磁阻。 自旋轨道耦合（SOC）是一种重要的磁结构耦合机制。在电子处于3d和4d壳层的系统中，SOC通常很弱。然而，在5d材料中，它可以定性地改变材料的基本性质，从而产生新的物理效应和新的器件概念。在这里，x射线和中子散射研究的晶格和磁性结构，以及它们的动力学性质，提出了两类5d化合物。(1)层状过渡金属二硫属化物。拟议的研究包括调查的全球和本地的晶格对称性，远程和本地二聚体的订单，以及它们的作用，破坏/促进奇异的超导性，磁秩序，和自旋极化电子带。 (2)准一维六角磁体表现出巨大的磁矫顽力和不寻常的磁各向异性。场致跃迁，微观磁相互作用和磁畴的研究提出。目标包括了解这些化合物中不寻常的磁性，它与5d电子物理学的关系，以及这种物理学是否可以深入了解永磁体的功能。