Crystal Structures and Magnetic Properties of New Quaternary Sulfides BaLn2MS5 (Ln=La, Ce, Pr, Nd; M=Co, Zn) and BaNd2MnS5

Crystal structures and magnetic properties are investigated for new quaternary sulfides BaLn2TS5 (Ln=La, Ce, Pr, Nd; T=Co, Zn) and BaNd2MnS5. These compounds crystallize in a tetragonal structure (space group I4mcm), which is isostructural with BaLa2MnS5. Their lattice parameters increase monotonically with the sizes of the lanthanide and transition metal. The increase of the a values is mainly due to the lanthanide size, and that of the c values is due to the transition metal size. In BaLn2CoS5, the Co2+ ions have the unquenched orbital moments. In BaNd2MnS5, the magnetic anomaly due to the antiferromagnetic ordering of the Mn2+ ion, is found at 63 K. Antiferromagnetic orderings for the Co2+ ions are observed at ca. 65 K in BaLn2CoS5 (Ln=La, Ce, Pr, Nd). For BaNd2TS5 (T=Mn, Co, Zn), the Nd3+ ions also show antiferromagnetic behavior below 6 K.