Low-energy ion-surface collisions have been observed to result in the emission of optical radiation arising from sputtering with simultaneous excitation. Emission functions have been obtained showing structure and energy thresholds which provide detailed information important in the understanding of this newly observed low-energy phenomenon. These data can be understood in terms of excited-state sputtering efficiencies and radiationless de-excitation processes which compete with radiative de-excitation of the excited states of the sputtered atoms.

• Received 6 July 1970

DOI:https://doi.org/10.1103/PhysRevLett.26.486