Strongly Correlated Electron Phenomena in Rare Earth and Actinide Intermetallics

稀土和锕系金属间化合物中的强相关电子现象

• 批准号: 0802478
• 负责人: M. Brian Maple
• 金额: $ 60万
• 依托单位: University of California-San Diego
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-04-01 至 2012-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0802478&HistoricalAwards=false
• 关键词: Strongly; Correlated; Electron; Phenomena; Rare

Technical: In rare earth and actinide materials, hybridization between localized f-electron and conduction-electron states yields novel phenomena such as heavy fermion behavior, non-Fermi liquid behavior, Kondo insulating behavior and superconductivity. The objectives of this research program are to characterize unconventional electronic ordered phases found in f-electron materials, determine the conditions under which they are formed, identify underlying microscopic mechanisms, and test relevant theories. These goals are sought experimentally through the measurement of the transport, thermodynamic, and magnetic properties of single crystals and thin films of novel rare earth and actinide compounds at low temperatures (down to the mK range), high magnetic fields, and high pressures. This investigation features three main thrusts: non-Fermi liquid behavior, unconventional superconductivity and other ground states, and the search for new correlated electron materials. Materials currently at the core of these studies include the CeMIn5 compounds, the Pr-based filled skutterudites, and U-based intermetallics such as URu2Si2. The study of strongly correlated electron phenomena in this laboratory serves to train the next generation of condensed matter and materials physicists who will contribute to academic, industrial, and governmental arenas throughout their careers. In addition to improving basic understanding of correlated electron behavior, these studies may also directly lead to technological advances such as thermoelectric refrigeration and magnetic information storage.Non-technical:The objective of this research program is to experimentally characterize the class of unusual strong interactions between electrons referred to as "correlated electron" behavior. Correlated electrons lead to a variety of interesting effects, such as superconductivity and unconventional magnetism. These phenomena are often observed in "f-electron" materials, those composed of rare earth or actinide elements, which include cerium and uranium. This investigation encompasses the synthesis of these f-electron materials and the subsequent experimental measurement of their electrical and magnetic properties. Via this approach, the different types of behavior attributed to correlated electron effects will be analyzed with the goal of better describing these effects and ultimately understanding the various conditions under which they occur. This investigation further involves a search for new materials exhibiting correlated electron behavior. This program serves to train the next generation of condensed matter and materials physicists who will contribute to academic, industrial, and governmental arenas throughout their careers. In addition to forming a deeper understanding of correlated electronic behavior, the knowledge developed from these studies may also lead to new advanced sensors, devices, and technologies for use in the energy, information, environmental, medical, and defense sectors.

技术支持：在稀土和锕系元素材料中，局域f电子态和导电电子态的杂化产生了新的现象，如重费米子行为、非费米子液体行为、近藤绝缘行为和超导电性。该研究计划的目标是表征f-电子材料中发现的非常规电子有序相，确定它们形成的条件，确定潜在的微观机制，并测试相关理论。这些目标是通过测量新型稀土和锕系化合物的单晶和薄膜在低温（低至mK范围），高磁场和高压下的传输，热力学和磁性来实验性地寻求的。这项研究的特点有三个主要的推动力：非费米液体行为，非常规的超导性和其他基态，并寻找新的相关电子材料。 目前这些研究的核心材料包括CeMIn 5化合物、Pr基填充方钴矿和U基金属间化合物，如URu 2Si 2。在这个实验室强相关电子现象的研究有助于培养下一代凝聚态物质和材料物理学家，他们将在整个职业生涯中为学术，工业和政府领域做出贡献。这些研究不仅有助于提高对关联电子行为的基本认识，还可能直接推动热电制冷和磁信息存储等技术的进步。非技术性：本研究计划的目的是通过实验表征电子之间的异常强相互作用，即“关联电子”行为。 相关电子会导致各种有趣的效应，例如超导性和非常规磁性。 这些现象经常在“f电子”材料中观察到，这些材料由稀土或锕系元素组成，其中包括铈和铀。这项调查包括这些f-电子材料的合成和随后的实验测量其电和磁性能。 通过这种方法，将分析归因于相关电子效应的不同类型的行为，目的是更好地描述这些效应，并最终了解它们发生的各种条件。 这项研究进一步涉及寻找表现出相关电子行为的新材料。 该计划旨在培养下一代凝聚态和材料物理学家，他们将在整个职业生涯中为学术，工业和政府领域做出贡献。 除了对相关电子行为形成更深入的理解外，从这些研究中获得的知识还可能导致新的先进传感器，设备和技术用于能源，信息，环境，医疗和国防部门。