Optical properties of Pt discontinuous films

The Pt films with mass thicknesses ranging from 0.8 to 4.7 nm were evaporated onto quartz-glass substrates under vacuum conditions (p similar to 10(-4) Pa) with evaporation rate similar to 0.01 divided by 0.2 nm/s. Transmittance spectra were measured in the wavelength range from 196 to 2500 nm. The microstructures were examined by electron microscope. The films with low coverage coefficient consist of islands regular in shape, they prevail in the structure. With coverage coefficient increase the islands become more irregular and join one with other. The experimental and calculated histogram are presented. It has been found that for the films examined the dependencies of transmittance on wavelength exhibit the minima which shift to longer wavelengths with coverage coefficient increase. These optical properties are typical for the island films. The structural examinations confirm island structures of the films examined.