Papers by Author: V.A. Trepakov

Abstract: Technology aspects and characterization of BaxSr1-xTiO3 (BST) films fabricated with low pressure plasma jet technique are presented. BST films were deposited on silicon coated with Pt/TiO2/SiO2 and on bare Si substrates. The nozzles-type RF hollow cathode has been fabricated from hot pressed BaTiO3, SrTiO3, and BST ceramics. Controlling of RF voltage, RF current and substrate temperature allowed us to deposit reproducible films with controlled grain size. Hysteresis loops, ellipsometric and micro-Raman investigation results are presented and discussed.

Abstract: The UV illumination effects in KTaO3 single crystals with Cu2+ impurity ions have been studied by electron paramagnetic resonance method. Single crystals both “as-grown” and thermally treated in oxygen atmosphere were investigated. It was found that the EPR signal of the Cu2+ centers decreases in the “as-grown” crystals during UV-irradiation at 365 nm, in the wholeinvestigated temperature range (3.7- 300 K). On the contrary, for the oxidized specimens a sizeable increase of the EPR signal of Cu2+ centers (except the signal from exchange coupled pair centers) is observed under UV illumination in some temperature regions.