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Information × Registration Number 0219U004731, 0119U001605 , R & D reports Title Highly-efficient red-emitting phosphors based on non-rare earth multicomponent oxides popup.stage_title Head Borkovska Lyudmyla, Registration Date 22-10-2019 Organization Institute of Semiconductor Physics popup.description2 The research objects are the powders and ceramics of manganese doped magnesium otrhotitanate produced by high temperature solid state reaction method. The aims of the work are the development of effective inexpensive environmentally friendly multicomponent red phosphors based on magnesium otrhotitanate activated by Mn4+ ions for illumination application and development of the methods for control of localization and charge state of Mn ions in the crystal lattice of magnesium otrhotitanate. Research methods are the photoluminescence, x-ray diffraction, electron paramagnetic resonance, diffuse reflectance. The multicomponent red phosphors based on manganese doped magnesium otrhotitanate, Mg2TiO4, in particular the phosphors of stoichiometric composition and those with excess content of magnesium oxide, MgO, are synthesized by the method of high temperature solid state reaction, as well as the additional annealing of the phosphors in the flow of nitrogen and oxygen are done. It is educed that manganese in Mg2TiO4 mainly has the charge state +4, Mn4+, and the largest intensity of red luminescence of Mn4+ ions is observed at the concentrations of dopant of 0.1 %. It is found that excess of MgO in an initial charge allows increasing the intensity of red luminescence of Mn4+ ions in 1.5-2 times and decreasing the amount of manganese in the charge state +2, Mn2+. It is proposed that excess of MgO promotes incorporation of manganese onto titan place and results in more uniform distribution of dopant in Mg2TiO4 grain. It is educed that additional annealing of the phosphors in the flow of oxygen at 600 °С results in the increase of intensity of red luminescence in 1.6-1.8 times, and the annealing in the flow of nitrogen - to the decrease of intensity of luminescence in 3-20 times and increase of amount of Mn2+ ions. Projected assumptions about the development of the research object are the improvement of the methods of fabrication of the phosphors based on manganese activated magnesium titanates with high intensity of red luminescence that can be used in white light-emitting diodes. Product Description popup.authors Ворона Ігор Петрович Корсунська Надія Овсіївна Стара Тетяна Русланівна popup.nrat_date 2020-04-02 Close