ENERGY DISTRIBUTION OF ATOMS SPUTTERED FROM POLYCRYSTALLINE METALS

The energy distributions of atoms sputtered from various polycrystalline metals by Kr+ ions of energies up to 1200 eV were determined using a spectroscopic time-of-flight method. Measurements of the Doppler shift of light emitted in the direction of travel by sputtered Mo and Ag atoms have verified the time-of-flight measurements. Average ejection velocities range from 4×105 (Ag) to 11×105 (Be) cm/sec; average ejection energies increase with the atomic number of the target atoms, while average velocities decrease. Higher sputtering yield materials tend to exhibit lower ejection energies. The crystal structure seems to play no important role in ejection energies. No evidence for focusing collisions could be derived from ejection energy data. © 1969 The American Institute of Physics.