Magnetic Correlations Through Metal-Insulator Transition in Strongly Correlated Electron Materials

强相关电子材料中金属-绝缘体跃迁的磁相关性

• 批准号: 0453804
• 负责人: Pengcheng Dai
• 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: 2005
• 资助国家: 美国
• 起止时间: 2005-06-01 至 2009-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0453804&HistoricalAwards=false
• 关键词: Magnetic; Correlations; Through; Metal; Insulator

***NON-TECHNICAL ABSTRACT***Understanding how complex behavior emerges from simple and basic laws is one of the areas of current interest in Condensed Matter Physics. This individual investigator project addresses the fundamental physical processes that give rise to novel phenomena, such as high-transition temperature superconductivity and colossal magnetoresistance (where a material displays a very large change in its electrical resistance when exposed to a magnetic field), resulting from the collective behavior of electrons. Materials in the family known as transition metal oxides (TMOs) exhibit these collective phenomena. Understanding these phenomena will not only enhance our knowledge of basic science, but also gives us the ability to design materials with novel and predictable properties. The objective of the program is to explore and understand the microscopic origins of various phases in the TMOs using neutrons as a probe. Neutron scattering experiments will be performed mostly at the upgraded high-flux isotope reactor (HFIR) at the Oak Ridge National Laboratory (ORNL) and on the new spallation neutron source at ORNL. The project will also utilize other world-class facilities in the U.S. and Europe when similar capabilities are unavailable at ORNL. The impact of this research program will include the training of the next generation of neutron scatters and elucidating the nature of the exotic properties of the TMOs. ***TECHNICAL ABSTRACT***This individual investigator project will establish an experimental program integrating neutron scattering experiments with lab based materials efforts. The aim of the project is to further our understanding of the phase transition from a Mott insulator to a metallic/superconducting state in transition metal oxides (TMOs). The objective of this research program is to explore and understand the microscopic origins of various phases in the TMOs using neutron scattering as a primary tool. The project will focus on electron-doped high-Tc superconductors and colossal magneto-resistance (CMR) manganese-oxides. The program has two components: advanced synthesis with initial materials characterization and neutron scattering. Neutron scattering, the core part of this research program, will be used to study the exotic spin and lattice dynamical properties of the highly correlated electron materials. Most experiments will be performed at the newly upgraded high-flux isotope reactor (HFIR) at the Oak Ridge National Laboratory (ORNL). However, other world-class facilities in the U.S. and Europe will be utilized when similar capabilities are unavailable at HFIR. Students will be trained in state-of-the art materials synthesis and neutron scattering techniques.

* 非技术性摘要 * 了解复杂的行为如何从简单和基本的法律出现是凝聚态物理学目前感兴趣的领域之一。这个个人研究项目解决了引起新现象的基本物理过程，例如高转变温度超导性和巨磁阻（当材料暴露于磁场时，其电阻显示出非常大的变化），这是由电子的集体行为引起的。被称为过渡金属氧化物（TMO）的家族中的材料表现出这些集体现象。理解这些现象不仅会增强我们的基础科学知识，而且会使我们有能力设计具有新颖和可预测特性的材料。该计划的目的是探索和理解TMO中各个阶段的微观起源，使用中子作为探针。中子散射实验将主要在橡树岭国家实验室（ORNL）升级的高通量同位素反应堆（HFIR）和ORNL的新的Spiral中子源上进行。该项目还将利用美国和欧洲的其他世界级设施，而ORNL没有类似的能力。这项研究计划的影响将包括下一代中子散射的训练和阐明TMO的奇异性质的性质。 * 技术摘要 * 这个个人研究项目将建立一个实验计划，将中子散射实验与实验室材料工作相结合。该项目的目的是进一步了解过渡金属氧化物（TMOs）从Mott绝缘体到金属/超导状态的相变。这项研究计划的目的是探索和了解TMO中的各个阶段的微观起源使用中子散射作为主要工具。该项目的重点是电子掺杂的高Tc超导体和巨磁阻（CMR）锰氧化物。该计划有两个组成部分：先进的合成与初始材料表征和中子散射。中子散射是本研究计划的核心部分，将用于研究高关联电子材料的奇异自旋和晶格动力学性质。大多数实验将在橡树岭国家实验室（ORNL）新升级的高通量同位素反应堆（HFIR）中进行。然而，当HFIR没有类似的能力时，将利用美国和欧洲的其他世界级设施。学生将接受最先进的材料合成和中子散射技术的培训。