Preparation of hcp-Ni(112-bar 0) epitaxial thin films on Au(100) single-crystal underlayers

Ni epitaxial films with an hcp structure are successfully obtained on Au(100) single-crystal underlayers formed on MgO(100) substrates at temperatures lower than 300 0C by molecular beam epitaxy. With increasing the substrate temperature, the volume ratio of more stable fcc phase increases in the film. The Ni film prepared at 100 0C consists primarily of hcp crystal with the (112-bar 0) plane parallel to the substrate surface coexisting with a small amount of fcc-Ni(100) crystal. The lattice constant of hcp-Ni crystal is determined as a = 0.249 nm, c = 0.398 nm, and c/a = 1.60.