Vibrational resonant desorption from surfaces using the infrared free-elctron laser

Abstract

The IRFEL is a useful infrared light source that can be employed as a probe of vibrational dynamics on surfaces. This paper will discuss the application of the IRFEL to desorb adsorbates from surfaces by resonantly exciting their vibrational modes. This application is illustrated by recent investigations of the resonant desorption of butane from Al2O(1120) using the Mark III IRFEL. These resonant desorption studies revealed a greater desorption yield for the asymmetric C-H stretches in comparison with the symmetric C-H stretches. This greeter desorption efficiency for the asymmetric C-H stretches was attributed to the orientation of the butane molecules in an ordered adlayer on A1203 (1120).