Nb_3X_4(X=S,Se,Te)的能带结构研究

固相过渡金属原子簇化合物Nb_3X_4(X=S,Se,Te)在低温下出现超导行为,且从S到Te,Nb_3X_4的超导转变温度Tc呈下降趋势。本文采用EHT近似下的紧束缚能带方法,计算了Nb_3X_4的能带结构。讨论其电子结构与超导电性的关系,并从化学键的观点出发对其Tc的递变加以解释。此外,本文还给出了Nb金属晶体的能带结构。

The Investigation on the Band Structures of Nb_3X_4(X=S,Se, Te)

The solid transtition-metal cluster compounds Nb3X4(X = S, Se, Te) are one kind of superconductors under low temperature, and it is known that their superconducting transition temperatures (Tc) decrease from S to Te. In this paper, the band structures of Nb3X4 have been studied by using the tight-binding energy band method within the Extend Huckel scheme. The relationship between the electronic structures and the superconductivity are preliminarily discussed. An explanation to their decreasing order in Tc is proposed from the viewpoint of chemical bonding. In addition, the band structure of crystal Nb is also presented for comparison.