Calculation of electron-energy-loss spectra of composites and self-similar structures

Abstract

We calculate electron-energy-loss spectra for self-similar systems of polarizable spheres using a previously developed theory for the electron-energy loss of a system of identical spheres. We do this by means of a recursive procedure and an effective ``local'' dielectric function, which contains, implicitly, the effects of spatial nonlocality due to correlations and multipolar interactions among the spheres, as well as some characteristics of the experimental setup. We also apply the procedure to systems of spheres with a continuum distribution of sizes. Finally, we propose a simple nonlocal generalization of Bruggeman's differential effective medium theory.