Local Atomic Structure of Non-Periodic Solids

本建议将衍射分析应用于结晶固体的局部原子结构，特别是超导氧化物和相关材料。最初的研究包括动力学对脉冲中子粉末衍射的影响（Plazcek校正）和使用脉冲中子直接观察晶格动力学。本研究随后使用二维对分布函数分析的新技术对单晶进行了衍射研究。这些观察结果在基于载流子诱导的局部晶格变形（极化子形成）的超导机制的背景下进行了检验。在这些研究的过程中，进一步发展了实空间衍射分析方法。从这些实验中得到的数据有助于进一步了解高温超导的微观机制。

This proposal applies diffraction analysis to the local atomic structure of crystalline solids, in particular superconducting oxides and related materials. Initial studies include the effects of dynamics on the pulsed neutron powder diffraction (Plazcek correction) and the direct observation of lattice dynamics using pulsed neutrons. This research is followed by diffraction studies of single crystals using a novel technique of two-dimensional pair distribution function analysis. The observations are examined in the context of the mechanism of superconductivity based upon carrier-induced local lattice deformation (polaron formation). In the process of these studies the real space method of diffraction analysis is further developed. %%% The data derived from these experiments are pertinent to furthering the understanding of the microscopic mechanisms of high temperature superconductivity.