Abstract
Crystallographic characteristics of ternary lanthanide sulfide compounds of lead were collected and their crystallochemical analysis was performed. New compounds were synthesized in PbS- Yb2S3 (2:1, 3:1, 4:1) systems. In the ratio PbS-Yb2S3 (4:1) there was detected the formation of a new compound Pb4Yb2S7. X-ray diffraction studies revealed that this compound was crystallized in the orthorhombic structure and had crystallographic characteristics as follows: a = 13.630Å, b = 23.481Å, c= 4.025Å, Vu.c = 1288.18Å3, Z = 4. A new possible structural motive was proposed for the Pb4Yb2S7 compound.