Electronic structures and stability of double-walled armchair (n,n)@(m,m) SiC nanotubes

In this work, we have investigated the stability and electronic properties of armchair double-walled SiC nanotubes (DWSiCNTs) based on density functional theory with the SIESTA package. The calculation has been performed on the armchair (4,4)@(n,n) and (5,5)@(n,n) DWSiCNTs with (n = 7-15). The stability calculation of DWSiCNTs shows that the armchair DWSiCNTs with difference chirality of 4, (n,n)@(n + 4,n + 4) and inter-wall distance of 3.65 angstrom are the most stable structures. Considering the electronic band structure points that all armchair nanotubes are semiconductors with indirect bandgap. Moreover, it is revealed that the value of the bandgap increases by increasing inter-wall distances, and the process of change at higher inter-wall distances be almost constant. In addition, the bandgap of double-walled SiC nanotubes is smaller than that of their single-walled nanotubes. The consequences of this investigation can certainly be helpful in future experimental studies.

Automated summary

In this work, the stability and electronic properties of armchair double-walled SiC nanotubes (DWSiCNTs) were investigated using density functional theory with the SIESTA package. The calculations were performed on armchair (4,4)@(n,n) and (5,5)@(n,n) DWSiCNTs with (n = 7-15). The stability calculation showed that the armchair DWSiCNTs with chirality difference of 4, (n,n)@(n + 4,n + 4) and inter-wall distance of 3.65 angstrom were the most stable structures. The electronic band structure revealed that all armchair nanotubes were semiconductors with an indirect bandgap. Furthermore, the bandgap increased with increasing inter-wall distances, and the rate of change became almost constant at higher inter-wall distances. Additionally, the bandgap of double-walled SiC nanotubes was smaller than that of their single-walled counterparts. These findings have important implications for future experimental studies.