Structural and electronic properties of copper nanowire encapsulated into BeO nanotube: First-principles study

We present a systematic study on the structural and electronic properties of close-packed Cu nanowires encapsulated in a series of zigzag (n,0) BeONTs using first-principles calculations. The initial shapes (cylindrical CuNWs and BeONTs) are preserved without any visible changes for the Cum@(n,0) (m=6 or 8, 8≤n≤14) combined systems. The most stable combined systems are Cu6@(10,0) and Cu8@(11,0) with an optimal tube-wire distance of about 2.8 Å and a simple superposition of the band structures of their components near the Fermi level. A quantum conductance of 3G0 is obtained for both Cu6 and Cu8 nanowires in either free-standing state or filled into BeONTs. The electron transport will occur only through the inner CuNW and the inert outer BeONT serves well as insulating cable sheath. So the Cu6@(10,0) and Cu8@(11,0) combined systems is top-priority in the ULSI circuits and MEMS devices that demand steady transport of electrons.