Electronic excitation during sputtering of silver atoms.

Abstract

The formation of metastable excited atoms during ion sputtering of polycrystalline silver was investigated by resonant laser postionization and time-of-flight mass spectrometry. It is shown that the metastable 4d95s2 D5y2 state with an excitation energy of 3.75 eV is populated with a surprisingly high probability of several percent with respect to the ground state. The velocity distribution of the metastable atoms is found to fall off more steeply towards high emission velocities than that of the ground state atoms, thus indicating a new excitation mechanism of the sputtered silver atoms.