Nature and structure of sub-nanometer defects in metal oxides by complex electron spectro-microscopy

本项目旨在开发一种用于探索固体电子结构的复杂电子能谱，并将其应用于表征金属氧化物和陶瓷材料中由几个到数百个原子组成的缺陷尘埃。作为结果，我们取得了以下成果：1.仪器的研制1.1用于阴极发光检测的新型透射电子显微镜样品夹具的研制1.2掠入射结构的波长色散X射线分析光谱仪的研制1.3电子能谱新的分析方法的发展2.1扩展能量损失精细结构的高级分析(反蒙特卡罗分析、时间分辨测量、小波变换简介)2.2利用起伏电子显微镜提取无序结构的中程有序2.3利用第一性原理量子化学计算对边缘结构附近的能量损失进行理论模拟2.4纳米压痕和有限元相结合的方法用于测量陶瓷在辐照下的力学性能3.应用3.1微小缺陷簇的检测和杂质氧缺陷的结构分析3.2气体离子辐照在陶瓷表面诱导起泡的表征3.3氢化纳米结构石墨中氢的分析3.4助剂陶瓷在汽车尾气净化催化剂中的电子结构分析

This project aims to develop a complex electron spectroscope TEM for exploring the electronic structures of solids and to apply it to characterize defect dusters consisting of a few to hundreds atoms in metal oxides and ceramic materials. As results we obtained the following achievements :1.Instrumental development1.1 Development of a new TEM specimen holder for detecting cathodoluminescence1.2 Development of wavelength dispersive x-ray analysis spectrometer with grazing incidence configuraion1.3 Equipment with hollow-cone illumination system in TEM2.Development of new analytsis methods for electron spectroscopy2.1 Advanced analysis of extended energy loss fine structure (Reverse Monte Carlo analysis, time-resolved measurements, introduction of wavelet transformation)2.2 Extraction of medium range order of disordered structures by fluctuation electron microscopy2.3 Theoretical simulations of energy loss near edge structure by first principle quantum chemistry calculations2.4 Development of combined method of nanoindentation and finite element method for measuring mechanical properties of ceramics under irradiation3.Applications3.1 Detection of very small defect clusters and structural analysis of impurity oxygen defect complex3.2 Characterization of gas ion irradiation induced blisters on ceramics surfaces3.3 Analysis of hydrogen in hydrogenated nanostructured graphite3.4 Analysis of electronic structures of promoter ceramic in catalysis for purifying automotive gas emission