SYNTHESIS, THERMAL ANALYSIS AND STRUCTURAL CHARACTERIZATION OF THE COMPOUND Ag2GeSe3

Abstract

The ternary compound Ag2GeSe3 belongs to the I2IVVI3 family of adamantane cationic derivation compounds with cubic anionic packing originating from the sphalerite structure. Polycrystalline samples synthesized by the transport method in the vapor phase, whose purity of the constituent elements 5N, were obtained. The Ag2GeSe3 semiconductor was characterized by differential thermal analysis, optical absorption and X-ray diffraction techniques, the results of which indicate that its melting point is at a temperature of 794 K, has a direct energy gap of 0.851 eV at pressure and room temperature, in turn the diffraction pattern shows the presence of 86.5% of the main phase Ag2GeSe3 and 11.5% of a secondary phase identified as GeSe. The refinement of the cell parameters establishes that the main phase of the compound Ag2GeSe3 crystallizes in a structure whose symmetry is monoclinic, with a space group C2 / c (No. 15), Z = 4, and whose value of the unit cell parameters are: a = 6.775 (8) Å, b = 22.581 (3) Å, c = 11.635 (5) Å, with an angle β = 97.08 (2) ° and the unit cell volume V = 1766.48 Å3. The refinement of parameters converged to the figures of merit M (20) = 11.2; F (20) = 21.2 (0.0052, 490); for 490 independent reflections.