Synthesis, structural characterization and differential thermal analysis of the quaternary compound Ag₂MnSnS₄

The quaternary chalcogenide compound Ag2MnSnS4 belonging to the system I2-II-IV-VI4 and synthesized by the melt and anneal technique, was characterized by Rietveld refinement of the powder X-ray diffraction data and differential thermal analysis (DTA). It was found that Ag2MnSnS4 crystallizes in the orthorhombic space group P m n 2 1, with unit cell parameters a = 8.1705 5 Å, b = 6.9413 5 Å, c = 6.6532 5 Å, and V = 377.33 5 Å 3, in a wurtzite-stannite structure. The DTA indicates that this compound melts at 790°C and that the phase relations which occurs in the material would be: α → α + α 1 → α 1 → α 1 + β → β → β 1 + L → L, were α is the orthorhombic wurtzite-stannite P m n 2 1 structure; α 1 is a high temperature modification; and β and β 1 are the zinc-blende structure and its high-temperature modification, respectively.