First-principles study on the magnetic and half-metallic properties of the Heusler alloy Ti2CoSn (110) surface

Abstract In this paper, we use the first-principles calculations based on the density functional theory to investigate the structural, electronic and magnetic properties of a symmetry Ti 2 CoSn (110) surface. The relaxations of the atoms are mainly occurred on the outmost three layers and the layer rumpling has a decrease tend from surface to inner layers. Unfortunately, the half-metallic character confirmed in bulk Ti 2 CoSn is destroyed on the (110) surface. The surface effects are mainly occurred on the outmost three layers, leading to not only a shift toward higher energy region in both channels of the DOS, a small surface state produced around the Fermi level in spin-down channel, but also a reduction in atomic magnetic moments with respect to those in the inner layers which are extremely close to the corresponding bulk values.