Dielectric function of aggregates of small metallic particles embedded in host insulating matrix

The optical properties of clusters with metallic spherical particles embedd ed in an insulating matrix are studied. A theoretical approach is proposed for the calculation of the macroscopic dielectric response for a collection of spheres at random positions embedded in a homogeneous medium. While acc ounting for the dipole-dipole interaction between particles, we have consid ered the frequency dependence behavior of the imaginary part of the effecti ve dielectric constant in this system with two kinds of particles of differ ent sizes. (C) 2000 American Institute of Physics. [S0003-6951(00)05014-2].