Dielectric function of Pd hydride thin films in terms of hydrogen concentration and film's thickness: A parametric formulation

An optimized parametric description of the dielectric function of thin granular Pd thin films is reported. The optical transmission spectra of 10, 15 and 20 nm thick films are measured and by means of an inversion procedure, the dielectric function of nano-sized Pd grains in the films is determined. Measurements are carried out for hydrogen pressures of up to 1 atm. The Brendel-Bormann model is used to describe in parametric form the dielectric function under these conditions.