Crystal structure of the RE2PbS4 (RE = Y, Dy, Ho, Er, and Tm) compounds and a comparison with the crystal structures of other rare earth lead chalcogenides

摘要

The crystal structure of the RE2PbS4 (RE = Y, Dy, Ho, Er and Tm) compounds (space group Cmc2(1), Pearson symbol oCl 12, a = 0.79301(3) nm, b = 2.86966(9) nm, c = 1.20511(5) nm, R-Bragg = 0.0979 for Y2PbS4; a = 0.79484(8) nm, b = 2.8721(3) nm, c = 1.2039(1) nm, for Dy2PbS4; a = 0.79081(2) nm, b = 2.86222(7) nm, c = 1.20220(4) nm, R-Bragg = 0.0859 for Ho2PbS4; a = 0.7863(2)nm, b = 2.8525(5)nm, c = 1.1995(2)nm, R1 = 0.0482 for Er2PbS4 and a = 0.78419(3) nm, b = 2.84184(9) nm, c = 1.19655(4) nm, R-Bragg = 0.0893 for Tm2PbS4) was investigated by means of X-ray single crystal and powder diffraction. Each RE atoms is octahedrally coordinated by six S atoms. Each Pb atoms is surrounded by seven S atoms to form a mono-capped trigonal prism.