CRYSTAL GROWTH OF ARGYRODITE Ag8GeS6

The mineral Ag8GeS6 is the first compound of a wide class tetrahedrally close packed phases united by common name argyrodites. Ternary argyrodites are complex chalcogenides formed on basis multi- and single-charged cations. Structural polyhedrons tetrahedra multicharged cation chalcogens, cations occupy voids. Argyrodites belong to promising solid-state conductors thermoelectric materials. This work aimed develop optimal conditions for single crystals growth method directional crystallization from melt. initial alloy was obtained using high purity elementary components two-stage single-temperature method. congruent nature melting (Tmelt = 958°C) passage structural phase transition Pna21 → F-43m at temperature 227 ° C confirmed DTA crystal grown melt regime selected taking into account thermal behavior based data. ~ 30 mm long 12 in diameter has medium degree cleavage. According results XRD analysis, it established that crystalline sample single-phase crystallizes low-temperature modification SG with following lattice parameters: 15.147 Å, b 7.469 c 10.584 Å.