High resolution electron energy loss study of Al_xGa_x__xAs mixed crystals

The surface optical phonon spectra of AlxGa1As mixed crystals have been measured by high resolution electron energy loss spectroscopy (HREELS). Two modes (Al-As and Ga-As types, respectively) were observed whose frequencies shifted almost linearly with aluminum concentration. The relative intensities of these modes are analyzed. Comparison is made with Raman scattering measurements and theoretical calculations. © 1986, American Vacuum Society. All rights reserved.