VIBRATIONAL-RELAXATION OF MOLECULES ON ALKALI-HALIDE SURFACES

We have mapped all the relaxation channels from vibrationally excited CO on NaCl (100). The relaxation rates of these channels are: dephasing at k(dph) almost-equal-to 10(11) s-1, radiative at k(rad) = 11 s-1, transfer to phonons at k(phn) almost-equal-to 2x10(2) s-1 and vibrationally induced desorption at k(vid) less-than-or-equal-to 10(-4) s-1. Theoretical models to account for all these rates are explored. Our understanding of the system CO on NaCl (100) allows us to make predictions of relaxation channels for other molecules on alkali halide surfaces.