Optical sum frequency studies of adsorption and laser-induced desorption of CO on W(110)

The adsorption and laser-induced desorption behavior of CO on W(110) has be en studied using sum frequency generation (SFG) and thermal desorption spec troscopy (TDS). The temperature and coverage dependence of the GO-stretch S FG-signal was measured. Laser irradiation of CO on the surface showed CO de sorption and almost no dissociation of CO by visible laser pulses of 15-45 mJ/cm(2) without damaging the surface. Simulations of the surface reactions are in agreement with these measurements. Furthermore, it was observed tha t the non-resonant SFG-intensity change caused by CO or O adsorption is cor related to the work function change. (C) 1999 Elsevier Science B.V. All rig hts reserved.