Analysis of Materials in Random System by Quantitative High-Resolution Transmission Electron Microscopy and Electron Diffraction

随机系统中的材料表现出归因于其结构的特性，从而使我们能够生产新的功能器件。拓扑或细胞随机系统中材料的结构分析是了解其性质的关键。本项目的目的是利用定量高分辨率电子显微镜（HRTEM）和电子衍射（ED）方法分析拓扑或细胞随机系统中各种材料的晶体结构。本课题所获得的结果已在下一节的文献中进行了报道。主要研究课题及结果如下：1。利用中子和同步x射线衍射方法分析了细胞随机体系中的BaSn_<2-x>Ti_xFe_4O_<11>、BiFeO_3、CaMn7O_<12>和ba_3ca_ <+x>Nb_<2-x bbb_4 O_<9-8>的晶体结构和磁性结构，并结合定量hrtem - 2的结果进行了讨论。采用横截面hrtem研究了冷铣削原子化Fe_<1-x>Al_x （x=0.35-0.42）粉末颗粒引起的铁磁性和结构畸变。在阴极发光扫描电镜的辅助下，利用HRTEM、ED和高角环形暗场STEM方法揭示了半导体srtio_3基陶瓷中氧空位和添加剂原子的分布，DRAM中O、N、P原子的分布，GaAs/AlGaAs多层异质结构中原子的扩散和沉淀以及光敏染料分子在AgBr表面的吸附等随机现象。能量色散x射线光谱学，电子能量损失光谱学。利用带能量滤光片的高分辨率电子显微镜在成像板上测量了Se、Sb和C非晶薄膜的ED强度，以阐明这些非晶薄膜的结构。对楔形晶体中出现的等厚条纹的强度进行了定量测量，并与能谱强度进行了相关。少

Materials in random systems exhibit characteristic properties which are ascribed to their structure, and thereby allow us to produce new functional devices. The structure analysis of materials in topological or cellular random system is the key point to understand their properties. The object of this project is to analyze the crystallographic structure of various materials in topological or cellular random system using quantitative high-resolution electron microscopy (HRTEM) and electron diffraction (ED) method. The results obtained in this project have been reported in literatures shown in the next section. The main subjects and results are as follows :1. The crystal and magnetic structure of BaSn_<2-x>Ti_xFe_4O_<11>, BiFeO_3, CaMn7O_<12> and Ba_3Ca1_<+x>Nb_<2-x>O_<9-8>, which are in cellular random system, have been analyzed using neutron and synchrotron X-ray diffraction method, and discussed taking account of the results of quantitative HRTEM.2. Ferromagnetism and structural distor … More tions induced in atomized Fe_<1-x>Al_x (x=0.35-0.42) powder particles by cold milling have been investigated using cross-sectional HRTEM.3. Random phenomena such as the distribution of oxygen vacancies and additive atoms in semiconducting SrTiO_3-based ceramics, the distribution of O, N, and P atoms in DRAM, the atom diffusion and precipitation in GaAs/AlGaAs multilayer heterostructure and the adsorption of photosensitive dye molecules on the AgBr surface have been disclosed using HRTEM, ED and high angle annular dark field STEM method with the aid of cathodoluminescence scanning electron microscopy, energy dispersive X-ray spectroscopy, electron energy loss spectroscopy.4. ED intensity of Se, Sb, and C amorphous films has been measured on imaging plates in a high-resolution electron microscope with an energy filter, to elucidate the structure of these amorphous films. The quantitative intensity measurements of equal thickness fringes appearing in wedge-shaped crystals, which are correlated with ED intensity, have been performed. Less