Neutron scattering studies of spin and lattice dynamics in electron-doped high-temperature superconductors and layered manganese oxides

这个NSF项目研究产生新颖的集体现象和自组装纳米结构的基本物理过程。已知表现出这些集体现象的材料是强相关电子过渡金属氧化物（TMOs）。对这些现象的理解不仅可以增强我们的基础科学知识，还可以使我们有能力设计出具有新颖和可预测性能的材料。具体来说，该实验项目将中子散射实验与实验室基础材料的努力相结合，旨在从根本上理解电子掺杂高转变温度（high-Tc）超导体和层状锰氧化物等TMOs中的自旋和晶格激发。该计划的目的是利用中子作为探针探索和理解TMOs中各种相的微观起源。中子散射实验将主要在橡树岭国家实验室新升级的高通量同位素反应堆（HFIR）上进行。然而，如果HFIR没有类似的能力，该项目也将利用美国和欧洲的其他世界级设施。这项研究计划的影响将包括下一代中子散射体的训练和阐明TMOs的奇异特性的本质。技术摘要：这个NSF项目解决了我们这个时代的主要新科学主题，即理解过渡金属氧化物（TMOs）中表现出的复杂自组织行为的基础和实际重要性。本研究计划的目的是利用中子散射作为主要工具，探索和了解TMOs中不同相的微观起源。特别是，该项目将重点研究电子掺杂的高转变温度（high-Tc）超导体和层状巨磁阻（CMR）锰氧化物。对于高温超导体，该项目将研究磁性和超导性之间相互作用的本质。对于CMR锰氧化物，该项目将重点了解微观自旋/晶格动力学如何决定这些材料的整体磁性和输运性质。中子散射实验是该研究项目的核心部分，将主要在橡树岭国家实验室（ORNL）新升级的高通量同位素反应堆（HFIR）上进行。然而，如果HFIR没有类似的能力，该项目也将利用美国和欧洲的其他世界级设施。这项研究计划的影响将包括下一代中子散射体的训练和阐明TMOs的奇异特性的本质。

NONTECHNICAL ABSTRACTThis NSF project addresses the fundamental physical processes that give rise to novel collective phenomena and self-assembled nano-structures. The materials known to exhibit these collective phenomena are the strongly correlated electron transition metal oxides (TMOs). The understanding of 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. Specifically, the experimental program integrates neutron scattering experiments with lab based materials efforts, aimed at the fundamental understanding of the spin and lattice excitations in TMOs such as electron-doped high-transition-temperature (high-Tc) superconductors and layered manganese oxides. The objective of the program is to explore and understand the microscopic origins of various phases in the TMOs using neutron as a probe. Neutron scattering experiments will be performed mostly at the newly upgraded high-flux isotope reactor (HFIR) at the Oak Ridge National Laboratory. However, the project will also utilize other world-class facilities in the U.S. and Europe when similar capabilities are unavailable at HFIR. 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 ABSTRACTThis NSF project addresses the dominant new scientific theme of our time, the fundamental and practical importance of understanding complex, self-organizing behavior exhibited 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. Specially, the project will focus on electron-doped high-transition temperature (high-Tc) superconductors and layered colossal magneto-resistance (CMR) manganese-oxides. For high-Tc superconductors, the project will investigate the nature of the interplay between magnetism and superconductivity. For CMR manganese-oxides, the project will focus on understanding how the microscopic spin/lattice dynamics determine the bulk magnetic and transport properties of these materials. Neutron scattering experiments, the core part of this research program, will be performed mostly at the newly upgraded high-flux isotope reactor (HFIR) at the Oak Ridge National Laboratory (ORNL). However, the project will also utilize other world-class facilities in the U.S. and Europe when similar capabilities are unavailable at HFIR. 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.