Open AccessSynthesis and some properties of compounds Cu2PrSb3S7 and Cu2ErSb3S7
Author(s) -
Reyhan M. Agayeva
Publication year - 2020
Publication title -
butlerovskie soobŝeniâ
Language(s) - English
Resource type - Journals
ISSN - 2074-0212
DOI - 10.37952/roi-jbc-01/20-64-11-13
Subject(s) - eutectic system , differential thermal analysis , phase (matter) , mole , phase diagram , crystallography , scanning electron microscope , dissolution , materials science , mole fraction , analytical chemistry (journal) , thermal analysis , thermal decomposition , chemistry , diffraction , thermodynamics , thermal , microstructure , chromatography , organic chemistry , physics , optics , composite material
The phase equilibrium in systems of CuSbS2 – PrSbS3 and CuSbS2 – ErSbS3 has been studied by physicochemical methods (Differential thermal analysis – DTA, X-ray diffraction phase analysis, Scanning Electron Microscopy – SEM analysis and microhardness testing) and their T-x diagrams were drawn. It was determined that both systems are quazibinary and characterized by formation of Cu2LnSb3S7 -type (Ln = Pr, Er) compounds. Cu2PrSb3S7 melts congruently at 1050 K and is the phase with unstable content. Its dissolution zone changes within concentration interval of 32-37 mole% of PrSbS3. Cu2PrSb3S7 divides the system into two sub-systems: CuSbS2-Cu2PrSb3S7 and Cu2PrSb3S7-PrSbS3. Both of sub-systems are eutectic. The coordinates of the eutectic point are like following: 15 mole % PrSbS3, T = 740 K and 50 mole % PrSbS3, T = 790 K. Cu2ErSb3S7 melts at 920 K by decomposition. At 725K between Cu2ErSb3S7 and CuSbS2 compounds in content of 15 mole % of ErSbS3 is formed eutectic balance. 4 mole % of solid solution is formed on base of CuSbS2. Both compounds are crystallized by naffildite-type structure in the form of rhombic syngonia (Cu2PrSb3S7 – a = 1.444; b = 2.146; c = 0.3995 nm; z = 4; Cu2ErSb3S7 – a = 1.430; b = 2.128; c = 0.380 nm; z = 4; stereogroup Pbnm or Pbn21).