Thermodynamics and Microstructure of Oxides

这项研究是创新延伸特别奖的更新。先前的赠款产生了很大的成效，在经过评审的科学期刊上发表了20多篇论文，另外还有5篇以上正在筹备中。重要成就的总结包括确定钛酸钡电介质中的缺陷结构非常依赖于材料的加工，化学计量差异很小；氧化铝固体电解质的缺陷结构既具有长程有序结构，又具有长程无序结构，这取决于化学计量学和热历史；对β -氧化铝中的混合离子效应进行了解释，并证明其与缺陷结构有关（同一材料的电导率变化多达数千倍）；采用离子交换技术合成了结构和性能更可控的固体电解质。续期资助将重点研究影响氧化物陶瓷结构和性能的关键化学因素，以及利用这种认识合成新的氧化物。正在研究的材料包括层状过渡金属氧化物、铜氧化物和镧系β氧化铝。使用的分析技术包括高分辨率电子显微镜、x射线衍射、拉曼光谱、红外光谱、热分析和电子表征（电导率、介电损耗、磁化率）。正在研究的材料具有重要的技术意义，因为它们在热电池、激光、高温超导体、通信介质等方面具有潜在的应用价值。

This research is the renewal of a special Creativity Extension Award. The prior grant was highly productive resulting in more than twenty publications in refereed scientific journals with more than five addition being prepared. A summary of the significant accomplishments includes determination that the defect structure in barium titanate dielectrics was very dependent upon the processing of the material with little difference in stoichiometry noted; the defect structure of beta alumina solid electrolytes has both long range order and long range disorder which depends upon the stoichiometry and the thermal history; the mixed ion effect in beta alumina was explained and shown to be related to the defect structure (conductivity varies by as much as several thousand times for the same material); solid electrolytes with more control of the structure and properties were synthesized using ion exchange techniques. The renewal grant will emphasize research on increased understanding of the critical chemical factors affecting the structure and properties of oxide ceramics and on synthesis of new oxides using this understanding. Materials being investigated include layered transition metal oxides, copper oxides, and lanthanide beta alumina. Analytical techniques used include high resolution electron microscopy, x- ray diffraction, Raman spectroscopy, infrared spectroscopy, thermal analysis, and electronic characterization (conductivity, dielectric loss, magnetic susceptibility). The materials being investigated have technological importance because of their potential application in thermal batteries, lasers, high temperature superconductors, dielectrics for communications etc.