Ag3Ge2S5Br: Synthesis, structure and ionic conductivity

Abstract

A new compound, Ag 3 Ge 2 S 5 Br, was found on the intersection of the Ag 3 SBr-GeS 2 and Ag 2 Ge 2 S 5-AgBr polythermal cross-sections of the Ag 2 S-GeS 2-AgBr system. The peritectic process L + GeS 2 ↔ ↔ ↔ ↔ Ag 3 Ge 2 S 5 Br takes place at T = 727 K. The crystal structure of Ag 3 Ge 2 S 5 Br was solved and refined using X-ray powder diffraction data: own structure type, space group P2 1 3-b 2 a 5 , Pearson symbol cP44, Z = 4, a = 10.16702(7) Å, R I = 0.0395, χ χ χ χ 2 = 3.19. Ag 3 Ge 2 S 5 Br was also obtained in the glassy state. The charge and mass transfer of the crystalline and glassy phases was investigated by the dc probe method between 250 and 495 K. The samples are purely ionic (Ag + , Br-) conductors. The influence of lining of the transport channels by the halogens (Br-, Ion on the conductivity of crystalline (Ag 3 Ge 2 S 5 Br + 10 wt.% GeS 2) and glassy (Ag 3 Ge 2 S 5 Br) samples was studied. Electronic structure calculations (FP-LAPW method) support the experimental results.

The Fast Silver Ion Conducting Solid-State Electrolytes for Deriving Thermodynamic Data

“…According to [48], the glass forming region in the Ag 3 GeS 3 Br-AgBr system is found to be 0-52 mol% GeS 2 . In this system the new quaternary phase Ag 3 Ge 2 S 5 Br (space group P2 1 3, a = 1.016702(7) nm, Z = 4 [49]) has been synthesized for the first time.…”

“…The electrical conductivity measurements of glassy and crystalline samples were performed by direct current probe method using different constructions electrochemical cells. It was found that the glassy materials are purely ionic conductors [48,49].…”