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

 

Chem. Met. Alloys 1 (2008) 288-292

 

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

 

The phase diagram of the quasi-binary Ag2SeЦAs2Se3 system was constructed using differential-thermal and X-ray phase analyses. The crystal structure of the ternary AgAs3Se5 compound (space group R-3m,= 0.38195(1) nm, = 5.0082(2) nm, RI = 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