Transport Size Effects in Double-Layer Polycrystalline Films

Abstract

We have systemized the results of theoretical investigations of different size effects in transport phenomena in bilayer polycrystalline films (BF), whose kinetic characteristics are essentially different as compared with the characteristics of bulk metals and thin films. A primary reason is a scattering of the charge carriers at both the external boundaries and the interlayer interface (the external size effect) and at the grain boundaries (the internal size effect). As a result of the scattering, the transport coefficients may be decreased (or increased) essentially with respect to the coefficients of metals, which formed the BF. The low-temperature grain-boundary interdiffusion of metals in bilayer films leads to some changes in the scattering power of the grain boundaries, and consequently, it leads to changes of the conductivity of the BF. Investigating the changes, we may determine the coefficients of the grain-boundary diffusion. The effects investigated theoretically in our review may be used for both the analysis of transport phenomena in bilayer polycrystalline films and the estimation of coefficients of the grain-boundary diffusion.

Keywords