Electronic transport properties of heterojunction devices constructed by single-wall Fe2Si and carbon nanotubes

Abstract

The electronic structures of the armchair Fe₂Si nanotubes are calculated by using the SGGA+U method. Novel heterostructure devices are prepared composed of single-wall Fe₂Si nanotubes (Fe₂Si NTs) and carbon nanotubes (CNTs). The results indicate that the (4,4) Fe₂Si NT is a ferromagnetic half metal with 100% spin-polarization ratio at the Fermi energy level. These heterojunctions have spin-polarized transport properties but their spin-polarization ratios are relatively low. Interestingly, the (13,0) CNT–(n,n) Fe₂Si NT–(13,0) CNT devices are all semiconductors but others are metallic. This study suggests that adding the novel Fe₂Si NTs endows the CNTs with spin-polarized property and provides very valuable results for better understanding of the electronic structures of the heterostructure.