X-ray emission from metal oxide crystals under dynamical electron diffraction conditions and its application to structure analysis

本项目是针对无序金属氧化物晶体中局部区域结构分析的新方法，如辐照的MgO、Al 2 O3和MgO·Al 2 O3，在与非弹性散射过程产生characteristic x射线的动态弹性散射的相互作用下，促进更好的理解。该项目研究于1997年开始，并对Mg-D1+的原子散射因子进行了测试。Iye D1和O Iye D12-Iye D1，通过高电压电子差异的400个反射MgO的关键电压的测量。The measured value of critical voltage 826 ± 3 kV is in quite good agreement with estimation based on the values of atomic scManagement ing factors fs and B-factors recently obtained by Rez等人And Zuo。这就是为什么F和B的价值在MgO及相关陶瓷化合物中的动态电子散射的定量分析中是可靠的。1998年第二年，电子通道增强的X射线微分析 ... More d the large angle convergent beam electron diffraction were simultaneously emManagement ed to determine cation configuration in Mgo·nAl2O3 crystals as a function of n and irradiation does with 1 MeV electrons or 300 KeV OイイD1+イエD1 ions。在辐射下，1 MeV电子到1.9 dpa的辐射下几乎没有改变。在1999年的最后一年，我们审查了一个高角度分辨率电子通道X射线光谱（HARECXS）作为一个预测性工具，在相同温度下与O-D1 + I-D1 ons的对比度D1 ons在相同温度下达到1.4 dpa。由HARECXS生成的X射线的方向相关强度分布是如此敏感，以至于能够确定确切地在水晶晶格晶格特定站点上的占用可能性。HARECXS has revealed partially disordered cation arrangement in Mgo·nAl2O3 irradiated with 1 MeV NeイD1+イエD1 ions as a function of depth from the irradiated surface。Less（低）

This project aimed for a new method of structural analysis on local areas in disordered metal oxide crystals, such as irradiated MgO, Al2O3 and MgO・Al2O3, promoting a better understanding on the interactions of dynamical elastic scattering of incident electrons with inelastic scattering process generating characteristic x-rays.The project research started in 1997 with examination on the atomic scattering factors of MgィイD1+ィエD1 and OィイD12-ィエD1, through the measurement of critical voltage for 400 reflection of MgO by high voltage electron diffraction. The measured value of critical voltage 826 ± 3 kV is in quite good agreement with estimation based on the values of atomic scattering factors fs and B-factors recently obtained by Rez et al. And Zuo. It was therefore concluded that their values of f and B are reliable in quantitative analysis of dynamical electron scattering in MgO and related ceramic compounds.In the second year 1998, the electron channeling enhanced x-ray microanalysis an … More d the large angle convergent beam electron diffraction were simultaneously employed to determine cation configuration in Mgo・nAl2O3 crystals as a function of n and irradiation does with 1 MeV electrons or 300 KeV OィイD1+ィエD1 ions. The cation distribution is hardly changed under irradiation with 1 MeV electrons to 1.9 dpa at 870K. On contrast significant displacements of cations are induced under irradiation with OィイD1+ィエD1 ions to 1.4 dpa at the same temperature.In the final year 1999, we examined high angular resolution electron channeling x-ray spectroscopy (HARECXS) as a proctical tool to locate lattice ions in spinel compounds. The orientation dependent intensity distribution of emitted x-rays obtained by HARECXS is so sensitive to ion configuration as to determine the occupation probabilities on specific sites in the crystal lattice accurately. HARECXS has revealed partially disordered cation arrangement in Mgo・nAl2O3 irradiated with 1 MeV NeィイD1+ィエD1 ions as a function of depth from the irradiated surface. Less