Structure and Raman spectra of (Cu6PS5I)1–x(Cu7PS6)x mixed crystals

Abstract

Mixed (Cu6PS5I)1–x(Cu7PS6)x crystals were grown using a direct crystallization technique. Being based on the X-ray diffraction data, their crystal structure was studied, showing face-centred cubic lattice for Cu6PS5I-rich solid solutions (х < 0.12) and primitive cubic lattice for Cu7PS6-rich (0.84 < x < 1) solid solutions. These structural data correlate with the Raman spectra where, besides the common features typical for the argyrodite-type Cu6PS5I and Cu7PS6 crystals, weaker bands characteristic only for the end-point compounds are revealed in the corresponding compositional intervals.

Keywords

• solid electrolytes
• mixed crystals
• crystal structure
• Raman scattering