Phase diagram of the Ag₂Se – As₂Se₃ system and crystal structure of the AgAs₃Se₅ compound

Chem. Met. Alloys 1 (2008) 288-292

https://doi.org/10.30970/cma1.0067

O.S. KLYMOVYCH, O.F. ZMIY, L.D. GULAY, T.A. OSTAPYUK

The phase diagram of the quasi-binary Ag₂Se–As₂Se₃ system was constructed using differential-thermal and X-ray phase analyses. The crystal structure of the ternary AgAs₃Se₅ compound (space group R-3m, a = 0.38195(1) nm, c = 5.0082(2) nm, R_I = 0.0868) was investigated using X-ray powder diffraction. The Se atoms form a close-packed arrangement with the layers stacked in the sequence ABC. The atoms of a statistical mixture M (0.5Ag+0.5As) and the remaining As atoms occupy 4/5 of the octahedral interstices.

Stacking of M-, Ag- and As-centered octahedra in the structures of the AsAsSe₂, Ag₂SnAs₆Se₁₂ and AgAs₃Se₅ compounds.

Keywords

Semiconductors / Phase diagram / Crystal structure / X-ray powder diffraction