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Information × Registration Number 0220U104403, 0120U104898 , R & D reports Title Elaboration of optimal conditions for the synthesis of solid solutions of wide bandgap oxides and monitoring of their structural, electrical and optical characteristics, as well as chemical composition popup.stage_title Head Khomenkova Larysa Y., Registration Date 16-12-2020 Organization VE Lashkarev Institute of Semiconductor Physics of the National Academy of Sciences of Ukraine popup.description2 Polycrystalline samples of undoped and doped with isovalent impurities of metal oxides were made and the influence of doping conditions and subsequent heat treatments on the optical, structural and electrical properties of the samples was analyzed. It is shown that doping of ZnO with Mg impurity promotes the formation of a solid solution of Zn1-xMgxO. Its bandgap depends nonmonotonically on the Mg content and sintering temperature. The hexagonal structure of Zn1-xMgxO forms via the competition of the formation of the hexagonal and cubic phases. The largest band gap is achieved for the Zn0,8Mg0,2O that corresponds to the upper limit of Mg solubility (20 at.%) in the hexagonal phase of the solid solution. Under thermodynamic sintering conditions, the temperature of 1000 - 1050 С and the annealing time of 3 h are optimal for ceramics' production. Optical properties of ZrO2 powders depend on the grain sizes. The PL spectrum of nanopowders is dominated by violet-blue components in contrast to the blue-green radiation of microcrystalline powders. It is shown that undoped ZrO2 powders can have a stable tetragonal structure when the average particle size does not exceed 10-12 nm. For the polycrystalline ZrO2 layers, the stabilization of the tetragonal phase is achieved due to the large surface area, which causes tensile stress. As the layer thickness increases, the tetragonal phase turns into a monoclinic one. The 500-nm Zr1-xGexO2 layers with a tetragonal structure has been produced. It is shown that with a Ge content higher than 20 at.%, the layers appeared to be amorphous being stable under annealing at 550–600 С. Further rise of annealing temperature up to 650-700C results in the phase separation and formation of Ge and ZrO2 inclusions. The technological conditions allowed Ge nanocrystals formation in amorphous ZrO2 host were found. Such samples can have a potenional memory application. Product Description popup.authors Kozoriz Kostantyn O. Ponomaryov Semen S. popup.nrat_date 2020-12-16 Close