Boylo I. Current transfer in tunnel structures with inhomogeneous oxide layers

The Ph.D. thesis is devoted to the study of physical mechanisms of charge and spin currents in solid-state heterostructures metal – insulator – metal with nano-scaled oxide interlayers caused by defects, spatial inhomogeneity of the oxide structure, and electronic ordering in the metallic electrodes. The aim of the study was to develop appropriate theoretical models able to describe qualitatively current-transfer processes in such systems and means of their experimental verification. The following results have been obtained: a general theoretical approach to calculations of transport characteristics of heterostructures with nano-scaled disordered insulating films based on elastic and inelastic tunneling effects in inhomogeneous potential barriers is developed; current-voltage and shot-noise characteristics of tunnel structures with defect centers inside a barrier interlayer were calculated, and a new method for the analysis of complex-oxide near-surface microstructure was proposed; an effect of non-equilibrium processes on the current transfer from a ferromagnetic metal to a superconducting film across high-transmission oxide layers was theoretically studied for the first time, and a novel approach to determination of a spin polarization of electrons in a magnetic electrode was proposed. Results of the thesis can be used for relatedscientific and research work in institutes of the NASU and universities of Ukraine.