Electronic structure and bonding properties of titanium silicides
Electronic structure and bonding properties of titanium silicides
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DOI：
10.1103/physrevb.57.4419
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发表时间：
1998-02
影响因子：
3.7
通讯作者：
M. Ekman;V. Ozoliņš
中科院分区：
文献类型：
--
作者：
M. Ekman;V. Ozoliņš
我们提出了一个从头算全势线性松芬锡轨道研究的结构和电子性质的七种化合物的二元Ti-Si体系。这些化合物的稳定结构为：$A3$ Ti, ${D8}_{8}$ ${\ mathm {Ti}}_{5}{\ mathm {Si}\ mathm {}}_{3}$, $B27$ TiSi，扭曲的TiSi ${L1}_{0}$, $C49$ ${\ mathm {TiSi}}_{2}$, $C54$ ${\ mathm {TiSi}}_{2}$和$A4$ Si。计算得到的生成焓与观察到的稳定结构的顺序一致，与实验得到的值吻合较好。本文最后对稳定相的电子结构和成键进行了分析，表明实验观察到的稳定相的性质与假设的不稳定结构的性质有很大的不同。因此，后者在一些稳定的Ti-Si化合物中代表了一个糟糕的键合模型。我们认为这些结构中的键具有复杂的特征，超出了简单的Ti-Ti和Ti-Si成对相互作用。
We present an ab initio full-potential linear muffin-tin orbital study of the structural and electronic properties of seven compounds of the binary Ti-Si system. The calculations were done with the compounds in their proposed stable structures, which are $A3$ Ti, ${D8}_{8}$ ${\mathrm{Ti}}_{5}{\mathrm{Si}\mathrm{}}_{3}$, $B27$ TiSi, TiSi in distorted ${L1}_{0}$, $C49$ ${\mathrm{TiSi}}_{2}$, $C54$ ${\mathrm{TiSi}}_{2}$, and $A4$ Si. The calculated enthalpies of formation reproduce the observed sequence of stable structures and agree reasonably well with the values deduced from experiments. The paper ends with an analysis of the electronic structure and the bonding in the stable phases, which shows that the properties of the experimentally observed stable phases differ considerably from those of the hypothetical unstable structures. Therefore, the latter represent a poor model for the bonding in some of the stable Ti-Si compounds. We suggest that the bonding in these structures has a complex character extending beyond simple Ti-Ti and Ti-Si pairwise interactions.