Strain-induced incomplete wetting at CuAu(001) surfaces

Abstract

X-ray reflectivity measurements, modeled on atomic scale by a dynamic approach, reveal a smooth Au top layer and subsequent Cu/Au layering at the (001) surface of CuAu crystals at high temperatures, enforced by a large surface field h1. Approaching the first order bulk transition the ordered near surface film grows but does not completely wet its disordered bulk phase as predicted. In contrast to earlier wetting experiments on heterogeneous systems which were dominated by surface roughness, we found strong lattice relaxations and incomplete wetting due to strain.