Bending vibration of NO on Pt(111) at the intermediate-excited state in photostimulated desorption

Abstract

Laser-induced desorption of NO from Pt(111) at 80 K is studied using a nanosecond-pulsed laser at 193 nm. The desorbed NO molecules are state-selectively detected by the resonance-enhanced multiphoton ionization method. The tilt angle at the time of NO desorption is estimated from the rotational quantum number dependence of the time-of-flight spectra for the desorbed molecules using a simple impulse model. The potential surface for the frustrated rotation (bending vibration) of NO chemisorbed on the Pt(111) surface is found to be nearly flat at the intermediate-excited state from an analysis of the mean vibrational amplitude.