Published online by Cambridge University Press: 10 February 2011
Structural evolution during initial epitaxial growth of Mo (111) and (110) on Al2O3 substrates has been studied using real-time reflection high energy electron diffraction and in-situ scanning tunneling microscopy. The Mo (111) growth on sapphire (0001) is initiated by the formation of small mound-like 3-dimensional (3D) islands that are correlated with unique length scales. The observed surface length scales depend on growth temperature and rate, and they coarsen as the thickness increases. The initial growth of Mo (110) on sapphire (1120) begins with layer-by-layer growth for the first monolayer, and subsequently the growth is 3D with mound-like features that are larger than those corresponding (111) counterparts. In both orientations lattice relaxation occurs within the first 2 – 3 monolayers.