Characterization of MgO(1 0 0) thin film growth on Mo(1 0 0)

Various MgO thin films grown on Mo(1 0 0) have been characterized by using metastable impact electron spectroscopy (MIES), ultraviolet photoelectron spectroscopy, low energy electron diffraction (LEED), and CO as a probe molecule to titrate defects. Using MIES and LEED, the as-grown MgO(1 0 0) films (thickness = ≈15 monolayers (MLs)) are found to be highly defective. Annealing at 1150 K significantly reduces the density of defects on the MgO(1 0 0) surfaces. CO adsorbs on the as-grown MgO(1 0 0) film at 90 K, whereas no CO adsorption was detected on the annealed MgO(1 0 0) film, in agreement with the MIES and LEED results. For MgO thin films with a thickness of 15 ML, no surface charging was observed during the UPS/MIES measurements.