Two dimensional imaging of photodesorbed species from surfaces and the desorption dynamics

Laser-Induced Desorption

“…The size of the pump laser beam on the sam ple was 1.5 x 1.5 mm 2 . As indicated by solid curves, these TOF spectra are fitted to a sum of two non-Maxwellian distributions (fast and slow components), each of the form S(t) = A/t 4 exp{-a(£/i) 2 …”

“…33 The mean translational en ergy {(E t )) is numerically calculated as flux-weighted kinetic energy using the form of A'v 3 exp(-av 2 thermal desorption channel via trapped in a shallow potential well such as the precursor state, since r tran s is as low as the sample temperature of 80 K. Figure 8 shows the internal-energy distributions of NO molecules in both the ft = 1/2 and 3/2 spin-orbit states and in v = 0 and 1 states at pump laser wavelengths of 193, 248, and 352 nm [Ref. 5].…”

Translational and Rotational Energy Distributions of NO Photodesorbed from Au(100)

“…Photon-induced chemical reactions including the desorption of small molecules such as NO, CO, or O 2 from solid surfaces have been a thriving area of research. − The aim of such investigations is typically to unravel and understand the basic processes that control the elementary steps, i.e., the mechanism and dynamics of adsorbate–substrate interactions during the desorption process. In this context, nitric oxide desorption from metal surfaces has been thoroughly investigated by many research groups using different experimental and theoretical methods. − NO has been the adsorbate of choice for many reasons, one of which is that NO is associated with many catalytic reactions in which it interacts with a surface . Another reason is that NO molecules in the gas phase can easily be detected state selectively by, e.g., resonance-enhanced multiphoton ionization (REMPI) or laser-induced fluorescence (LIF) spectroscopy.…”