Desorption of O2 from a stepped platinum(113) surface during 308 nm laser irradiation

Angular and velocity distributions of desorbing O2 during irradiation of 308 nm laser pulses were studied on a stepped Pt(1 1 3) surface. With increases in the coverage, three desorption components collimated at around 128, 308 and 508 successively appeared when the desorption angle was changed in a plane along the step edge. The translational temperature also showed maxima at these collimation angles, and the values were slightly lower than previous results for 193 nm irradiation. Some possible desorption mechanisms are discussed. # 2001 Elsevier Science B.V. All rights reserved