CAREER: Correlating the Microstructure with the Physical Properties of Perovskite and Related Oxide Materials

这个CAREER项目的重点是了解钙钛矿和相关氧化物（PRO）中具有有趣和有用的离子传输特性的离子传输机制。具体而言，本项目将研究PRO's的微观结构与其物理性质的相关性，以阐明影响离子电导率的结构和组成因素。本项目采用新颖的3,3',3"-硝基三丙酸前驱体凝胶法低温合成不同组成和晶粒尺寸的纳米晶PRO（如La0.6Sr0.4MnO3），并利用x射线衍射（XRD）和高分辨率透射电子显微镜（HRTEM）结合阻抗谱对纳米晶PRO进行表征，研究其结构、组成、以及物理性质（特别是离子传输）。结构和电导率数据将被分析和关联，以确定晶粒尺寸、晶界、缺陷和空位在大块离子扩散中的关系。本科学生将参与这些氧化导电材料的合成、表征和物理分析。这个CAREER项目将对PRO中控制离子传输的机制产生新的见解。由于钙钛矿的可能组成及其电子和离子输运性质仍然相对不明，因此本研究中影响纳米晶PRO离子导体中离子电导率的结构和组成因素的成功研究将对固态PRO导体领域做出相对重大的贡献。更好地了解PRO中的离子传输将对从便携式设备到家庭和车辆等众多应用中的经济和商业障碍产生重大影响。此外，该项目还将对南方大学（一所历史悠久的黑人学院和大学，也是一所主要的本科院校）中代表性不足的少数民族学生产生重大影响，让他们接触到与材料科学相关的研究，这是一个少数民族学生非常稀缺的领域。学生将有机会获得实践经验，从而获得更有意义的本科研究经历。

This CAREER project focuses on understanding the mechanisms that govern ion transport in perovskites and related oxides (PRO) with interesting and useful ionic transport properties. Specifically, this project will investigate the correlation of microstructure of PRO's with their physical properties to elucidate the structural and compositional factors that influence the ionic conductivity. The project involves the low temperature synthesis of nanocrystalline PRO's such as La0.6Sr0.4MnO3 with varying compositions and crystallite sizes using the novel 3,3',3"-nitrilotripropionic acid precursor gel method and the characterization of the nanocrystalline PRO's using X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM) in conjunction with impedance spectroscopy to investigate the relationship between structure, composition, and physical properties (ion transport in particular). Structural and conductivity data will be analyzed and correlated to determine the relationship between grain size, grain boundaries, defects and vacancies on bulk ion diffusion. Undergraduate students will participate significantly in the synthesis, characterization, and physical analysis of these oxide-conducting materials.This CAREER project will yield new insights into the mechanisms that govern ion transport in PRO's. Since the possible composition of perovskites and their electronic and ionic transport properties remain relatively unexplained, the successful investigation of the structural and compositional factors that influence the ionic conductivity in nanocrystalline PRO ion conductors in this study will represent a relatively significant contribution to the area of solid-state PRO conductors. A better understanding of ionic transport in PRO's will have a significant impact on the economic and commercial barriers in a multitude of applications ranging from portable devices to homes and vehicles. Additionally, this project will also have a significant impact on under-represented minority students at Southern University, a Historically Black College and University and a Primarily Undergraduate Institution, by exposing them to materials science-related research, a field where the numbers of minority students are very scarce. Students will be given the opportunity for hands-on experience that results in a more meaningful undergraduate research experience.