SUPERCONDUCTIVITY AND MAGNETISM IN CHEVREL-PHASE RARE-EARTH MOLYBDENUM SELENIDES SINGLE-CRYSTALS REMO(6)SE(8) (RE=GD, DY)

Chevrel phases containing rare-earth atoms (REMo(6)X(8); X = S, Se) ar e model systems which can present at the same time, phenomena of super conductivity and long-range magnetic interactions. We have recently de veloped a new crystal growth method specific to the selenides series, which was applied to RE = Gd Dy, Ho, Er and Yb. We present results obt ained on single crystals of GdMo6Se8 and DyMo6Se8. A discussion of the crystal growth method and of the ternary phase relations is done, and results are compared to those obtained for the binary isostructural c ompound Mo3Se4.