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Information × Registration Number 0218U001792, 0118U001459 , R & D reports Title Doped composite oxide materials for photonic applications popup.stage_title Head Markevich Iryna Vasylivna, Registration Date 27-09-2018 Organization Institute of Semiconductor Physics popup.description2 The object of the study - undoped and doped with manganese thick films and ceramics of MgO-TiO2 composites, produced by the method of high-temperature solid-state reaction. The purpose of the work is to find out the effect of doping with manganese on the "red" photoluminescence of magnesium titanates and to establish the nature of excitation and radiation centers responsible for this luminescence in composites based on magnesium titanates. Research methods - photoluminescence, Raman scattering, X-ray diffraction, electron paramagnetic resonance, diffuse reflection, transmittion electron microscopy. It is shown that the crystalline phase of Mg2TiO4 is formed at temperatures of 1100-1200 ° C, and MgTiO3 at 800-1200 ° C. It is found that all undoped and doped with manganese composites of MgO-TiO2 exhibit a narrow "red" photoluminescence (PL) band with a maximum of 660 nm in the Mg2TiO4 phase and 701 nm in the MgTiO3 phase, characterized by two broad excitation bands in the UV and blue-green spectral ranges. It is shown that an increase in the concentration of Mn from 1017 cm-3 to 1020 cm-3 leads to an increase in the intensity of the "red" PL. The electron paramagnetic resonance method detected a residual manganese imputiry in all undoped powders of MgO and composites of MgO-TiO2. It is established that the "red" PL in the undoped MgO-TiO2 composites is due to forbidden 2Eg - 4A2g radiative transitions of Mn4 + ions, and the corresponding PL excitation bands are caused by allowed 4A2 - 4T1 and 4A2 - 4T2 transitions of Mn4 + ions in the MgTiO3 and Mg2TiO4 phases. It is found that the addition of 0.5 wt. % Li promotes formation of phases of magnesium titanates at lower annealing temperatures and allows to increase the intensity of "red" luminescence in several times. Assumptions about the development of the research object are the improvement of the technology for the production of red phosphors based on magnesium titanates activated by manganese with a high intensity of "red" luminescence, which can be used for the manufacture of white LEDs. Product Description popup.authors Борковська Людмила Володимирівна Стара Тетяна Русланівна Хоменкова Лариса Юріївна popup.nrat_date 2020-04-02 Close