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Information × Registration Number 0223U004990, 0121U109484 , R & D reports Title New superionic argyrodite based conductors for highly effective solid-state energy sources popup.stage_title Head Kokhan Oleksandr P., к.х.н. Registration Date 12-12-2023 Organization Uzhhorod National University State Higher Educational Institution popup.description2 Based on the data of differential thermal analysis (DTA) and X-ray diffraction analysis (XRD), close to optimal technological regimes for the synthesis and growth of single crystals of solid solutions of Ag7(Ge1-xSix)S5I composition (where x = 0, 0.2, 0.4, 0.6, 0.8, 1.0) were developed . The methodology for the preparation of superionic ceramics based on micro- and nanocrystalline powders of Ag7(Ge1-xSix)S5I solid solutions has been improved. The obtained single crystalline and ceramic (obtained from micro- and nanocrystalline powders) materials were studied using X-ray diffraction and microstructural (scanning electron microscopy and energy dispersive X-ray spectroscopy) analyses, optical methods (diffuse reflection, optical transmission, spectral ellipsometry), electrical conductivity (impedance spectroscopy) and microhardness measurements. The mechanism of the Ag7(Ge1-xSix)S5I solid solutions formation has been established for the first time. Using the density functional theory, it was found that the cationic substitution Si+4→Ge+4 leads to an increase in the stability of the crystal lattice. Studies of microhardness changes within the framework of the gradient theory of plasticity indicate plastic deformation of single crystals and ceramic samples of Ag7(Ge1-xSix)S5I solid solutions. According to the results of electrical conductivity measurements by impedance spectroscopy, single-crystal and ceramic samples of Ag7(Ge1-xSix)S5I solid solutions are characterized by a rather low value of the electronic and high values of the ionic components (σion>>σel) of conductivity. It has been shown that reducing the size of crystallites (applicable to ceramic materials) leads to an increase in the ionic component of conductivity, which makes it possible to increase the overall manufacturability of materials for practical applications. Using optical methods, the presence of a compositional disorder of the crystal structure at cationic Si+4→Ge+4 substitution was established.   Product Description popup.authors Bilanych Vitaliy Stepanovych Malakhovskaya Tetiana O. Pohodin Artem I. Pop Mykhailo M. Shender Iryna O. popup.nrat_date 2023-12-12 Close