Abstract
A new technique specially designed to use Auger electron spectroscopy for the measurement of very low sputtering yield has been applied for low energy (0.1-6 keV) proton sputtering of molybdenum and pyrolytic graphite. In molybdenum the sputtering yield above 1 keV is about three times as large as the experimental one obtained by Finfgeld, and below 1 keV it rapidly decreases with decreasing energy. In graphite physical sputtering yield at 500°C is about an order of magnitude larger than that of molybdenum, whereas the energy dependence is very similar to the molybdenum case. But the energy dependence is very different from the theory of Weissmann and Sigmund. The measured temperature dependence of the chemical sputtering yield for pyrolytic graphite at 1 keV shows the maximum value of about 0.08 CH4 molecules/ion near 750 K.
