Investigation of the R2S3–Cu2S–PbS (R = Y, Dy, Ho and Er) systems

The interactions between the components in the R2S3–Cu2S–PbS (R = Y, Dy, Ho and Er) systems at 870 K were determined using X-ray single crystal and powder diffraction. The existence of the compounds RCuS2 (R = Y, Dy, Ho and Er) and the solid solutions Y(2+x)/3Cu2−xS2 (0 ≤ x ≤ 0.52), Dy(2+x)/3Cu2−xS2 (0 ≤ x ≤ 0.55), Ho(2+x)/3Cu2−xS2 (0 ≤ x ≤ 0.61), Er(2+x)/3Cu2−xS2 (0 ≤ x ≤ 0.58) was confirmed in the R2S3–Cu2S (R = Y, Dy, Ho and Er) sections. The existence of the compounds R2PbS4 (R = Y, Ho, Dy, Er) and the solid solution Dy2+2x/3Pb1−xS4 (x = 0.44–0.50) was established in the R2S3–PbS (R = Y, Dy, Ho and Er) sections. The formation of the compounds Y5+xCu1−xPb3−xS11 (x = 0.28), Dy5CuPb3S11, Ho5Cu1+xPb3−x/2S11 (x = 0.25), Er5CuPb3S11 in the R2S3–Cu2S–PbS (R = Y, Dy, Ho and Er) systems was established at the first time, the existence of the compounds R3.33CuPb1.5S7 (R = Y, Dy, Ho and Er) and RCuPbS3 (R = Y, Dy, Ho and Er) was confirmed.