Surface magnetism in vanadium overlayers on W(100)

Abstract Localized surface magnetism in materials with non–magnetic bulk is a subject of considerable interest. In particular, in the case of strained transition metal overlayers on transition metals substrates, the interaction overlayer–substrate can lead to a fascinating magnetic behavior where the competition between strain and hybridization controls spin–polarized states. In this work, we have studied the structural, electronic, and magnetic properties of V overlayers on W(100). We report full potential linearized augmented plane wave (FLAPW) calculations, within the local density approximation (LDA), the generalized gradient approximation (GGA) and the hybrid functional B3LYP for the exchange–correlation part of the total energy, including spin–orbit coupling. A magnetic to non–magnetic transition was found in the surface layer as a function of the number of atomic vanadium layers. For the monolayer and bilayer cases, we found that the strong hybridization between the overlayer 3 d –orbitals and the substrate 5 d –orbitals define the characteristics of the surface density of states, resulting in a magnetic moment of 1.06 μ B , 1.42 μ B , 1.21 μ B and 0.53 μ B , 1.07 μ B , 0.71 μ B at the surface layer of 1 V / W ( 100 ) and 2 V / W ( 100 ) in the LDA, GGA and B3LYP, respectively. In contrast, for 3V/W(100), the surface density of states presents a strong localization due to the strain generated by the substrate; in this case, the magnetism disappears. The effects of the strain and the hybridization of the 3 d – 5 d orbitals of the overlayer–substrate on the local electronic band structure of the surface layers are discussed.