Discontinuous metal films on dielectric substrates, their optical and electrical properties, structures and statistical descriptions

A brief survey of some results concerning optical and electrical properties of discontinuous metal films on dielectric substrates and their statistica l description is given. Optical properties (transmittance and imaginary par t of dielectric permittivity spectral of AZ Cu and Mn discontinuous films a re presented and interpreted in terms of effective medium theories; modifie d Maxwell-Garnett and Bruggeman. The ranges of dielectric properties, the p ercolation threshold, and the range of metallic properties are determined f or optical and electrical properties of the film examined. The consideratio ns concerning electrical properties include such conduction mechanisms as m etal conduction, substrate conduction quantum tunneling thermally activated tunneling and hopping. Real structures of the films are examined making us e of electron microscope. Also the computer model for determining the contr ibution of the fundamental conduction mechanisms in discontinuous films is introduced. The inverse power law is used to describe the structure and the statistical distributions of inhomogeneous films of Ay Cu, and Mn on diele ctric substrates. To this end, the rank of an island is connected with its area for the films with different coverage coefficients (metal content). Th e dependencies of the island areas on the rank orders in a double-logarithm ic plot are straight lines according to the Mandelbrot law. The slope of th e straight line characterises the ranges of the distributions of the island s: i) the log-normal or the Gaussian one (with two parameters of statistica l distribution - the mean value and the variance), ii) the Poisson distribu tion (with one parameter - the mean value), iii) Levy stable distribution ( the parameters of distribution are infinite). The correlation between optic al and electrical properties of discontinuous metal films and their structu res and statistical description is found.