Energy loss spectra of thin ®lms of aluminum on niobium

Thin ®lms of aluminum were deposited on a niobium substrate. The energy spectrum of re¯ected electrons was recorded to determine the energy loss mechanisms. The energy loss spectra of the thin ®lms differed from those of the pure metals. Peaks were observed in the loss spectrum of the thin ®lms which could be attributed to the excitation of interface plasmons at the boundary between the aluminum ®lm and the niobium substrate. The energy of the interface plasmon is a few percent less than the theoretical value. # 2001 Elsevier Science B.V. All rights reserved