Electronic Structure and Properties of the Alkaline Earth Monosilicides
Electronic Structure and Properties of the Alkaline Earth Monosilicides
复制标题
碱土单硅化物的电子结构和性能
DOI：
10.1021/jp205825d
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发表时间：
2012
影响因子：
3.7
通讯作者：
R. Nesper
中科院分区：
文献类型：
--
作者：
E. C. Reyes;R. Nesper
作为先前工作的延续，这里对碱土单硅化物（AESi；AE = Ca、Sr 和 Ba）的电子结构进行了彻底研究。我们在密度泛函理论层面采用了几个第一原理代码。 AESi被发现是金属的，在费米能级具有低态密度。导电性发生在金属 d 态和硅 p 态网络上。我们讨论了增加阳离子尺寸不仅会导致能带变平，还会导致硅反键态的减少和费米表面的收缩。费米面的类空穴分支比类电子分支具有更强的各向异性；随着阳离子尺寸的增加，前者的各向异性似乎会增加，接近二维金属特征。估计的形成热与之前的实验结果相当吻合。
In continuation of a previous work, the electronic structure of the alkaline earth monosilicides (AESi; AE = Ca, Sr, and Ba) is thoroughly investigated here. We employ several first principles codes at the density functional theory level. AESi are found to be metallic with a low density of states at the Fermi level. The conductivity takes place over a network of metal d- and silicon p-states. We discuss how increasing cation size causes not only a flattening of the bands but also a depopulation of silicon antibonding states and the shrinking of the Fermi surface. The hole-like branch of the Fermi surface is more anisotropic than the electron-like; the anisotropy of the former seems to grow, approaching two-dimensional metallic features, as the cation size increases. Estimated heats of formation are in fairly good agreement with previous experimental results.