Theoretical study of α - and γ -V 2 O 5 double-walled nanotubes

Abstract

The first-principles calculations of the atomic and electronic structure of double-walled nanotubes (DWNTs) of γ -V 2 O 5 have been performed and the obtained properties have been compared with those of α -V 2 O 5 ones. The DWNT structure relaxation leads to the formation of two types of local regions: (1) adhesion regions and (2) puckering regions. Although the structure of adhesion regions of α -V 2 O 5 DWNTs is close to the structure of bulk α -V 2 O 5 , this is not the case for γ -V 2 O 5 DWNTs. The resulting structure of adhesion regions in γ -V 2 O 5 SWNTs allows us to assume the existence of hypothetical stable phases, with one of them resembling the experimentally observed R-Nb 2 O 5 and (V 0.7 Mo 0.3 ) 2 O 5 crystals.