Nuclear dynamics during the N1sautoionization of physisorbedN2

We demonstrate that even for adsorbed molecules, the vibrational fine structure of resonant core hole decay channels after narrow-band excitation can show a dependence on the variation of the primary excitation energy as known from isolated molecules. Despite several adsorption-induced broadening mechanisms, the so-called detuning effect can be observed in the autoionization of a ${\mathrm{N}}_{2}$ monolayer physisorbed on Xe/Ru(001) for the $1{\ensuremath{\pi}}_{u}^{\ensuremath{-}1}$ final state of participant decay, in good agreement with theoretical predictions and observations for isolated ${\mathrm{N}}_{2}.$ However, contrary to the corresponding decay channel of isolated ${\mathrm{N}}_{2}$ and to the theoretical predictions for it, the decay into the $3{\ensuremath{\sigma}}_{g}^{\ensuremath{-}1}$ final state shows clearly different behavior much closer to that of normal Auger decay. This is partly due to final-state broadening.