The influence of size effect on the coefficients characterizing reflection, transmission, and absorption of microwaves by polycrystalline metal films is studied. Using the example of gold films, the article examines the influence of internal size effect due to their polycrystalline structure on the value of the parameter that determines the dependence of the , and coefficients on the film thickness. It was found that, depending on the value of the reflection coefficient of electrons striking the grain boundaries, parameter calculated using the Mayadas-Shatzkes-Janak (MSJ) theory for grain size effect differs significantly from that obtained in calculations based on the use of the Fuchs-Sondheimer theory for thickness size effect. The dependence of on the parameters determining the grain growth rate and limiting grain size has been established, which made it possible to reveal the effect of the film microstructure on the dependence of the , and coefficients on the film thickness. Based on the revealed character of the dependence of on the parameters of the MSJ theory and the structural parameters of the film, recommendations are proposed for choosing the metals that are most optimal for producing coatings for electromagnetic interference shielding.
Influence of the grain size effect on the coefficients of reflection, transmission, and absorption of microwaves by the polycrystalline metal films