The reflectivity spectra of Al3Ni and AlNi3

The reflectivity spectra of Al3Ni and AlNi3 as deduced by near-normal reflectivity measurements in the photon energy range 1-4 eV, are compared with theoretical calculations using the linearized muffin tin orbitals (LMTO) method. Good agreement is obtained between theory and experiment. Electron energy loss spectroscopy (REELS) measurements have also been carried out on both compounds in the range 0-35 eV, utilizing 2 keV electrons, in order to explore the high energy regions of the optical functions and verify its reliability in determining optical constants. In spite of the REELS poor resolution with respect to spectrophotometric techniques, a fair agreement is found between the results obtained by the two spectroscopies. (C) 1997 Elsevier Science B.V.