STUDIES ON LANTHANOIDS-ANTIMONY-CHALCOGENIDES. I. SYNTHESIS AND CRYSTAL DATA OF THREE NEW LANTHANUM ANTIMONY CHALCOGENIDES

Three new La–Sb chalcogenides were synthesized by hydrothermal or evacuated silica tube methods. (1) LaSbO2S2: a bright-red needle crystal; crystal system, hexagonal; space group, P63/m; lattice constants, a=14.954(3), c=3.898(2) A, and Z=6. (2) La6Sb8S21: a blackish-red columnar crystal with metallic luster, orthorhombic, P222, a=14.317(2), b=15.239(4), c=8.685(1) A, and Z=2. (3) La3Sb3S10: a bright-red platelike crystal, monoclinic, a=13.209(6), b=14.229(6), c=5.583(1) A, β=94.54(3)°, and Z=2.