【摘要】 对Fe Si合金相图中α2 相的结构进行了模型构造 ,指出α2 相并非为B2 型简单体心立方结构 ,而是一种类似于B2 型结构的超结构 ,其中包含着以Fe原子和Si原子为中心的两种不同的结构单元。Fe原子和Si原子按照这种方式在空间交替排列时 ,位于中心的Si原子仍保持为正四面体结构 ,这与硅晶体的实际结构是相吻合的。利用固体与分子经验电子理论对其进行了价电子结构计算 ,结果表明 ,α2 相中的共价电子主要集中在最强的FeⅠ —Si和FeⅠ —FeⅡ 键上。对其脆性和强度进行了电子理论分析。更多还原

【Abstract】 A structural model of α 2 phase of Fe Si binary system was constructed, which shows that α 2 phase is not a simple bcc structure, but a kind of superstructure being similar to B 2 type of structure. It contains two different kinds of structural units, which is the one with centered Fe atom and the one with centered Si atom. When they arrange alternatively in space, the central Si atoms can keep the tetrahedron structure, which is in a good agreement with the real structure of silicon crystal. Based on the empirical electron theory of solids and molecules the valence electron structure of α 2 phase was calculated and the calculated results show that the covalence electrons mainly focus on the strongest bonds of Fe Ⅰ—Si and Fe Ⅰ—Fe Ⅱ. The brittleness and strength of α 2 phase were analyzed by using the electron theory. [更多还原