Half-metallic ferromagnetism in vanadium chalcogenides

Using an accurate density-functional method, we systematically explore vanadium chalcogenides in various crystal structures in order to find half-metallic (HM) ferromagnets which could possibly be fabricated as thin films with a thickness sufficient for real spintronic applications. The zincblende and wurzite (WZ) phases of VTe and the WZ phase of VSe are found to be HM ferromagnets with a magnetic moment of 3.000 mu(B)/formula unit. Their HM gaps of, respectively, 0.31, 0.60, and 0.25 eV are 0.53, 0.56, and 0.52 eV higher in total energy/formula unit than the ground-state NiAs phase of VTe and therefore could possibly be realized in the form of films with great enough thickness. Their HM ferromagnetism persists even when the volume is compressed by 10, 20, and 5%. As they are compatible with the well-known binary semiconductors, these HM ferromagnetic phases, when realized experimentally, may be useful in spintronic applications.