Resonant electron transfer in the emission of ion-beam sputtered metal atoms studied by double resonance laser ionization

We report the measurements of population partitions and state-specific kine tic energy distributions of ground and metastable state Sr, Co and Ni atoms ejected during Ar+ ion-beam sputtering of clean polycrystalline targets. T o obtain this information we use a very sensitive and generally applicable method based on resonance laser ionization mass spectrometry. The experimen tal results show a strong dependence on the correspondence of the electroni c configuration of the atomic state with the bulk electronic structure and are discussed in view of resonant electron transfer as a mechanism for the emission of metal atoms in excited states. (C) 2000 Elsevier Science Ltd. A ll rights reserved.