Growth, atomic structure, and oxidation of chromium overlayers on W(110)

Abstract
Novel structural and chemical properties of Cr monolayer, bilayer, and multilayer films on W(110) have been identified using temperature programmed desorption, low-energy electron diffraction, and Auger electron spectroscopy. A pseudomorphic (1×1) Cr monolayer forms at T>100 K which is stable up to desorption at ∼1290 K despite a ∼9% lattice mismatch. The second monolayer forms a metastable (2×2) structure in the 500 K <T<800 K range, for which a quad-cluster model is proposed. An (11×11) coincidence lattice is observed for multilayer films. Oxidation of the Cr overlayers leads to both an interfacial oxide and Cr2O3-like phases. Cr2O3/W(110) incommensurate epitaxy is observed for thick Cr films.