Semiconducting iron disilicide films on Si(111): A high resolution electron energy loss spectroscopy study

摘要

Thin films of bgr;‐FeSi2on Si(111) have been studied by low energy electron diffraction (LEED) and high resolution electron energy loss spectroscopy (HREELS). The observed LEED pattern is consistent with two possible epitaxial orientations. HREELS measurements demonstrate the semiconducting character of the films. The energy gap is determined toEgbartil;0.92 eV–0.33 meV/KT(K). Additionally a number of optical phonons is found in the range between 200 and 500 cm−1. Theoretical spectra are calculated with optical phonon parameters obtained from infrared data and are compared with the measured spectra.