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Information × Registration Number 0214U002757, 0113U004866 , R & D reports Title Microwave tunable materials, composites, and devices - 984091 popup.stage_title Head Belous Anatolii, Registration Date 28-01-2014 Organization V.I.Vernadskii Institute of General and Inorganic Chemistry NASU popup.description2 Report on the 1st stage of R&D. 33 pp., 15 figs., 3 tables.. Object of research - composite polycrystalline materials based on solid solutions Ba0.6Sr0.4TiO3 (BST) with the perovskite structure and different concentrations of Mg - containing impurities (MgO and Mg2TiO4), composite structures based on these materials, and microwave resonant nonlinear components - coaxial dielectric resonators (CDR) .. The purpose of this project - the development of new nonlinear dielectric materials , composite structures and microwave components with low dielectric losses and high sensitivity to the applied electric field. As a result of Stage 1 of the R&D new single-phase and multiphase (composite ) nonlinear materials based on ferroelectric solid solutions (Ba1 - xSrx) TiO3 (BST).have been developed and investigated. The influence of the chemical composition , heat treatment and sintering conditions on the content of crystalline phases, microstructure, dielectric and nonlinear properties of polycrystalline materials have been studied. The influence of the type and concentration of impurities of magnesium oxide compounds (MgO, MgTiO2, Mg2TiO4) sintering conditions on the properties of composite materials based on (Ba1 - xSrx) TiO3 (x = 0.4-0.6) have been examined. It has been shown that the presence of impurities contributes to lowering the sintering temperature of the ceramic material and obtaining a homogeneous crystal structure and low porosity. The resulting nanostructured materials demonstrated high permittivity ( = 400 - 1000) , a high non-linearity (nR 20 - 30%) and low loss (tg << 10-1). New compositional elements " cavity resonator - ferroelectric / semiconductor " system have been developed on the basis of (Ba1 - xSrx)TiO3 to produce experimental samples of coaxial dielectric resonators (CDR) with the value of dielectric constant = 150 and = 250 . Operating frequency of CDRs (f) varied from 300-400 MHz. It was found that when connecting the power supply to the element " ferroelectric / semiconductor ", a stabilization of the operating temperature of the CDR occurs ( and respectively - the operating frequency ), which depends on the applied voltage and the CDR type . As a result of the project activities, science-technical cooperation between scientists from Ukraine, Slovenia, and UK has been established. OXIDES, FERROELECTRICS, TUNABLE MATERIALS, PEROVSKITES Product Description popup.authors В'юнов Олег Іванович Дурилін Дмитро Олександрович Коваленко Леонід Леонідович Овчар Олег Вікторович Плутенко Тетяна Олександрівна Соловйова Катерина Дмитрівна Солопан Сергій Олександрович Ступін Юрій Дмитрович Хоменко Борис Семенович popup.nrat_date 2020-04-02 Close