Facile Transformation of Isolated Fragments to Infinite Chains in Rhenium Chalcocyanide Clusters: Synthesis and Structure of (Pr4N)2M(H2O)5 [Re6X8(CN)6]·H2O and (Pr4N)2M(H2O)4[Re6S8(CN)6] (X=S, Se; M=Mn, Ni)

Magnetic properties have been studied for the perovskite Pr1-xBaxCoO3 (0x0.5). Ferromagnetic order is observed below ~190 K for x0.2 in dc susceptibility-temperature curves. Magnetic circular dichroism spectra were measured for a ferromagnetic phase at Co-L2,3, Pr-M4,5, Ba-M4,5, and O-K edges. It is revealed that the Co ion has both spin and orbital moments. It is also observed that the Ba 4f orbitals have a localized moment and exhibit ferromagnetic order at low temperatures, though Ba2+ is expected to be almost only in a nonmagnetic 4f0 state. Magnetic order is observed also for Pr 4f and O 2p.