Grain boundary bondings in ceramics by spatially resolved EELS

在谷物边界发挥中央作用中确定宏观材料中的缺陷被吸收，而不是期望在单一晶体材料中。在许多类型的陶瓷中存在的缺陷已被假定。关于这些影响的定量信息，由于它们的束缚状态在高分辨率电子显微镜耦合与亚纳米级分辨率电子能量损失光谱学之前没有被澄清。EELS）.在目前的研究中，我们调查了MgO中硅的化学物质，如一个例子。O-K edge， Si-L-D223 L-D2 edge， Mg-L-D223 L-D2 edge ELNES （electron Energy loss near edge structure）通过使用我们的计算第一原则分子轨道方法获得的理论结果得到了测量和比较。模型集群大约由100个原子用于计算。作为一个结果，在MgO矩阵中存在六个协调的硅原子。

Impurities adsorbed at the grain boundary play central roles in determining macroscopic properties that can not be expected in single crystal materials.The presence of impurities has been assumed in many kinds of ceramics.However, quantitative information on these impurities as well as their bonding states has not been clarified before the recent progress of high resolution electron microscopy coupled with sub-nano meter resolution electron energy loss spectroscopy(EELS).In the present study, we investigated chemical states of Si in MgO as an example. O-K edge, Si-LィイD223ィエD2 edge, Mg-LィイD223ィエD2 edge ELNES (electron energy loss near edge structure) were measured and compared with theoretical results obtained by our calculations using first principles molecular orbital method.Model clusters composed of approximately 100 atoms were used for the calculation.As a result, presence of six-fold coordinated Si atoms in the MgO matrix can be recognized.