Ionic Dielectric Function of α -AgI Based upon Hubbard-Beeby Theory

Abstract

A frequency and wave vector dependent dielectric function of α -AgI is studied by using a phonon description based on a modified Hubbard-Beeby theory. The frequency dependent dielectric function is characterized by a main LO phonon peak and a sub LA phonon peak. The frequency spectrum for the dielectric function is consistent with those for the ac conductivity and the charge density dynamical structure factor of α -AgI.