Sachanyuk V. Phase Equilibria and Properties in the Quasi-ternary Systems Formed by the Chalcogenides of 3d- and Ib, IIb, IIIa, IVa,b Elements

Using XRD and microstructure analysis results, isothermal sections of the phase diagrams of 9 quasi-ternary systems at 298 K were constructed. Phase equilibria in 11 quasi-binary systems were investigated (of which 8 at 870 К, and 3, at 670 К). Phase diagrams of 11 systems were constructed for the first time (of these, 6 are quasi-binary, and 5 are partially quasi-binary). We discovered 35 quaternary chalcogenides of which 27 are new compounds. The crystal structure of 32 compounds was investigated by X-ray powder method. They crystallize in seven structure types, one of which is a new type (Cu2MnZrS4 and Cu2MnZrSe4 (space group P3m1, structure type Cu2MnZrS4)). The genesis of the structure of the quaternary compounds to the binary analogs and elementary sybstances was studied. The homogeneity regions of the intermediate phases of the systems and of the solid solution ranges of AICIIIX2 compounds were determined. The crystal structure of 37 solid solutions was refined. The mechanism of the formation ofthese phases was determined. Six single crystals of quaternary chalcogenides were grown. The dopant, Mn, with the content close to the intrinsic defect concentration (N=2,0•1020 cm-3) improves the optical quality of the AgGaGe3Se8 crystals by decreasing the absorption in the transparency region to К 16 cm-1. Using the radiation-induced diffusion that allows us to decrease the absorption К 10 cm-1, we developed the technique of "radiation annealing" for the clarifying of AgGaGe3Se8. The AgCd2-xMnxGaS4 alloys are photosensitive materials in the 530-610 nm range. This allows the use of these materials as photoelements. The Ag0,5Cr0,5Ti0,5S2, CuCrTiS4, Cu2CrZr3S8, Cu2MnZr3S8, Cu2FeZr3S8, Cu2CoZr3S8 and Cu2NiZr3S8 compounds may be used as electrode-active substnaces in graphite-paste sensors. The sensitivity limits of such electrodes in the potentiometric determination of Сu2+ are 10-9 М, that for Ag+ is 5.0·10-6 М.