TIME-CORRELATED LASER-DESORPTION OF NO FROM NIO(100) NI(100)/

The desorption of NO molecules with femtosecond UV laser pulses (lambd a = 314 nm, 550 fs) from a thin film of NiO(100)/Ni(100) is investigat ed with vibrational state selectivity. A superlinear dependence of the yield Y on the laser intensity, Y similar to I-n (1.3 less than or eq ual to n less than or equal to 1.6), is found, although with much weak er dependence on I than for metal substrates. Time-resolved two-pulse correlation measurements performed with different pulse intensities yi eld a high transient vibrational excitation. The behaviour of the tota l vibrational excitation is simulated using an electronic friction app roach. (C) 1998 Published by Elsevier Science B.V. All rights reserved .