Crystal structures of the RCuPbS3 (R = Tb, Dy, Ho, Er, Tm, Yb and Lu) compounds

• Published in: Journal of alloys and compounds 2005-08, Vol.399 (1-2), p.189-195
• Main Authors: GULAY, L. D, OLEKSEYUK, I. D, WOŁCYRZ, M, STEPIEN-DAMM, J
• Format: Article
• Language: English
• Subjects: Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Inorganic compounds; Physics; Structure of solids and liquids; crystallography; Structure of specific crystalline solids
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2005.03.036

The crystal structures of the RCuPbS3 (R = Tb, Dy, Ho, Er, Tm, Yb and Lu) compounds (space group Cmcm, Pearson symbol oC28-4) were determined by means of X-ray single crystal diffraction (a = 0.3925(l) nm, b=1.2916(4)run, c=1.0161(3)nm, R1=0.0376 (HoCuPbS3); a=0.3916(1) nm, b=1.2934(3) nm, c=1.0106(2) nm, R1=0.0304 (ErCuPbS3); a=0.3911(1) nm, b=1.2956(3) nm, c= 1.0064(3) nm, R1=0.0441 (YbCuPbS3); a=0.3899(1) nm, b=1.2920(4) nm, c=1.0030(3) nm, R1=0.0320 (LuCuPbS3)) and X-ray powder diffraction (a=0.39413(3) nm, b =1.2885(1) nm, c = l .0262(1) nm, R(Bragg)=0.0907 (TbCuPbS3); a =0.39297(3) nm, b =1.2891(1) nm, c =1.0205(1) nm, R(Bragg)=0.0851 (DyCuPbS3); a = 0.39096(3) nm, b = 1.29539(9) nm, c=1.0078(1)nm, R(Bragg)=0.0943 (TmCuPbS3)). The structure of these compounds is related to the structure of KZrCuS3 and can be described as a packing of R-centered octahedra, Cu-centered tetrahedra and Pb-centered trigonal prisms. The structures of the RCuPbS3 (R = Tb, Dy, Ho, Er, Tm, Yb and Lu) compounds are closely related to the structure of YCuPbS3 (beta-BaLaCuSe3 structure type, space group Pnma) where S atoms form similar motifs and the positions of cations are identical.