Shemet V. Phase equilibria and crystal structures of the compounds in the Y2X3 - Cu2X - Pb(Sn)X (X=S, Se, Te) and Y2X3 - Cu2X - SnX2 (X=S, Se) systems

Isothermal sections of the systems Y2X3 - Cu2X - PbX (X=S, Se, Te), Y2X3 - Cu2X - SnX (X=Se, Te) and Y2X3 - Cu2X - SnX2 (X=S, Se) have been constructed at 870 K and of the Y2S3 - Cu2S - SnS system at 720 K. The existence of 6 ternary compounds has been confirmed and the formation of 7 new ternary and 10 new quaternary compounds has been established in investigated and some related systems. The crystal structures of all compounds have been determined. Most of the ternary and quaternary compounds possess constant composition; the homogeneity regions are observed only for the ternary Y2/3Cu2X2 (Y0,84Cu1,48S2 - Y2/3Cu2S2, YCuSe2 - Y2/3Cu2Se2 and YCuTe2 - Y2/3Cu2Te2) and quaternary Y3Cu1-4xSn1+xS7 (x = 0-0,09) compounds. The compounds crystallize in 17 structure types; 6 of them (YCuS2, Y6Pb2Se11, ScCuSe2, Y3,33CuPb1,5S7, Y3Cu1-4xSn1+xS7 (x=0,09), Y2Cu0,20Sn0,95S5) crystallized in own structure type. The comparison of the investigated and related systems has been discussed. The relations between the investigated in present work structure types and known from literature structures have been discussed.