Evidence of alkali adatom island formation induced by ion bombardment on a Na covered Pt surface

We report on adatom island formation induced by Ne+ ion bombardment on a Na covered Pt surface. By using the collisionally excited autoionization electron spectroscopy (CEAES) we observe that, for large initial coverages, ion impact causes the Na adatom aggregation creating large surface areas which are relatively Na-rich and Na-depleted. Decay of excited atoms above these alkali islands and above the more or less clean Pt substrate zone with very different work functions results in the splitting of each atomic transition line in two well separated components.