Growth and morphology of ultrathin Mn films on Au(001) surface investigated via scanning tunneling microscopy

Abstract We investigate the room-temperature growth of ultrathin Mn films on Au(001) surface for Mn thicknesses ( d Mn ) up to 1.5 nm. The surface structure and morphology at various d Mn are investigated via scanning tunneling microscopy and low-energy electron diffraction (LEED). Although the formation of surface Au-Mn alloy is observed at d Mn = 0.3 nm, body-centered-tetragonal (bct) Mn(001) films grow epitaxially in a layer-by-layer mode at d Mn = 0.6 and 1.0 nm, showing a p(1 × 1) LEED pattern with the in-plane lattice constant of Au(001). The surface morphology comprises primarily atomically flat terraces with spiral growth patterns at d Mn = 1.0 nm. At d Mn = 1.5 nm, three-dimensional islands are observed, thus indicating a growth-mode change from layer-by-layer to layer-plus-island. The differential-conductance spectrum for d Mn = 1.0 nm shows distinct peaks at −0.07 and −0.45 V, which may correspond to the spin-polarized surface states of the bct Mn(001) film surface.