Ordered and Disordered Defects in Perovskite Related Structures With An Emphasis on Superconducting Oxides

这项研究是正在进行的调查的延续， 钙钛矿的缺陷结构和电学性质， 相关氧化物陶瓷。 镧铜氧化物中的材料 将在此期间进行调查。 实验技术，如平衡电 在恒定氧活度和恒定化学组成下的电导率 组成，库仑滴定，电子显微镜（包括 选择区域衍射，暗场成像，和网格化， 将用于提供有关缺陷的定量信息 浓度，传导机制，以及缺陷排序 这些材料中的一些。 一个域模型， 纳米结构水平已被提出来解释观察到的 部分氧化的，受体掺杂的，成员的行为 相关的锶-铁-钛氧化物体系。 这些材料非常类似于 组成和结构类型的超导氧化物。 提高对缺陷结构性质的认识 以及其与这些材料的电性能的关系将 有助于更好地了解 超导性

This research is a continuation of ongoing investigation of the defect structure and electrical properties of the perovskite- related oxide ceramics. Materials in the lanthanum-copper oxide system will be investigated during this grant period. Experimental techniques, such as equilibrium electrical conductivity at constant oxygen activity and constant chemical composition, coulombic titration, electron microscopy (including selected area diffraction, dark field imaging, and latticing, will be used to give quantitative information on defect concentrations, conduction mechanisms, and on the defect ordering that occurs in some of these materials. A domain model at the nanostructure level has been proposed to explain the observed behavior of partially-oxidized, acceptor-doped, members of the related strontium-iron-titanium oxide system. These materials are remarkably similar to the superconducting oxides in both compositional and structural type. An improved understanding of the nature of the defect structure and its relation to electrical properties of these materials will lead to an improved understanding of the mechanisms of superconductivity.