Measurements of the characteristic electron energy loss spectra of aluminum and magnesium were made (in a reflection experiment) during oxidation of a fresh evaporated layer of either metal. It was found that surface oxidation results in the rapid disappearance of the low-lying energy losses (10.3 ev in aluminum and 7.1 ev in magnesium) and the appearance of modified low-lying losses of 7.1 ev in aluminum and 4.9 ev in magnesium. The general changes in the loss spectra and the particular changes in the spectrum of aluminum were in good agreement with the predictions of Ferrell and Stern.

• Received 26 October 1959

DOI:https://doi.org/10.1103/PhysRev.118.640