Rare-earth germanium antimonides RE6Ge5-Sb11+ (RE = La-Nd, Sm, Gd-Dy).: II.: Magnetic and transport properties

Magnetic and transport properties have been measured for the series of ternary rare-earth germanium antimonides RE6Ge5-xSb11+x (RE = La-Nd, Sm, Gd-Dy). All are metallic, with the members containing RE other than La displaying kinks in their resistivity vs temperature curves; the To and Dy members exhibit Kondo-like behavior with resistivity minima occurring at 10 and 150 K, respectively. For the compounds with RE = Ce, Pr, Nd, Sm, Gd, Tb, the magnetic susceptibility and electrical resistivity measurements reveal long-range antiferromagnetic ordering with T-N less than or equal to 22 K. At 2 K, the Ce, Pr, and Nd members undergo metamagnetic transitions at critical fields between 1.0 and 4.0 T, while the Gd member displays spin-flop behavior with H-SF = 1.85 T and H-C = 5.75 T. The single-crystal magnetoresistance of the Gd member below Th shows an orientationally dependent steplike behavior of resistivity as a function of field with changes in resistivity coinciding with the same critical fields observed in the magnetization measurements.