Phase relations along the Ag8GeS6–[(AgBr)4·GeS2] cross-section.
Crystal structure and electric conductivity of Ag6GeS4Br2
in bulk
Chem.
Met. Alloys 3
(2010) 161-168
https://doi.org/10.30970/cma3.0153
Mykola V. MOROZ, Pavlo Yu. DEMCHENKO, Lev G. AKSELRUD, Oleksiy G. MYKOLAYCHUK,
Roman E. GLADYSHEVSKII
The Ò–õ-diagram of the Ag8GeS6–[(AgBr)4·GeS2] polythermal cross-section has been
constructed in the range 25-100 mol.%Ag8GeS6. The conditions for solid-state synthesis of the Ag6GeS4Br2 quaternary phase have been established. The crystal
structure of Ag6GeS4Br2 (Pnma – d 8c7a, oP96-44.24,
Z = 4, a = 6.53892(5), b =
7.72656(5), c =
22.90338(17) Å; X-ray powder diffraction,
820 reflections measured, 58 parameters refined, RI = 0.0383, Rp = 0.0408, Rwp =
0.0528, χ2 = 1.76) is a disordered variant of the structure
determined previously on single crystal data. The electrical conductivity of Ag6GeS4Br2 has been measured by the dc probe method between 250 and 410 K. A model for the superionic electrical conduction mechanism is proposed.
Bulk crystal structure of Ag6GeS4Br2
(left) and temperature dependences of the electrical conductivity (right).
Keywords
Ag–Ge–S–Br / Phase
diagram / Crystal structure / Electrical conductivity / Superionics