Self-assembling of alloy nanostructures on van der Waals surfaces

Abstract

We report on the growth of alloys ( CrPt 3 , VPt 3 , FePt) on the (0 0 0 1) surface of the layered compound WSe 2 , by co-deposition of 3d-metal and Pt atoms under ultra-high vacuum conditions. Because of weak interactions with the Se hexagonal dense planes and the strong lattice mismatch, the adatoms self-assemble and form epitaxial 3D nanostructures, which adopt lattice parameters very close to those of bulk phases. This type of growth is called quasi-van der Waals epitaxy and would allow the fabrication of nanostructured media of potential interest for magnetic recording technology. The structure and morphology of the nanostructures were studied by reflection high-energy electron diffraction, scanning tunnelling microscope and grazing incidence small angle X-ray scattering. These first results suggest that both the type of long-range chemical ordering ( L 1 2 or L 1 0 ) and the elastic properties of alloys play a role in the final morphology of nanostructures.