Pb on Mo(110) studied by scanning tunneling microscopy

Scanning tunneling microscopy (STM) has been used to investigate the growth behavior of ultrathin Pb films on the Mo(110) surface at room temperature. The analysis of STM measurements indicates that for a coverage θ<1 ML two-dimensional growth of the first Pb monolayer (wetting layer) took place. Above θ>1 ML , the three-dimensional growth of the Pb islands with strongly preferred atomic scale “magic height” and flat top is observed. At coverages between 1 ML<θ≤2 ML , only islands containing two atomic layers of Pb are observed. At coverages between 2 and 3 ML, islands containing two and four atomic layers of Pb are observed. At higher coverages θ>3 ML , the island height distribution shows peaks at relative heights corresponding to N=(2,4,6,7, and 9) of Pb atomic layers.