CHARACTERIZATION OF ADSORPTION STATES OF ATOMIC IODINE ON PT(111)

Temperature-programmed desorption (TPD), X-ray photoelectron spectroscopy (XPS), work function change (DELTA-phi) and photoelectron yield measurements have been made for atomic iodine on Pt(111). By correlation with known adsorbate structures formed at various coverages, we conclude that atomic iodine in threefold hollow and onefold atop sites have distinguishable thermal and electronic properties. The results, particularly the conclusion that threefold hollow I gives a negative DELTA-phi, whereas onefold atop I gives a positive DELTA-phi, are interpreted in terms of a recent theoretical model.