Rare-earth germanium antimonides RE_6Ge_(5-x)Sb_(11+x) (RE=La-Nd,Sm,Gd-Dy).II.Magnetic and Transport Properties

摘要

Magentic and transport properties have been measured for the series of ternary rate-eath germanium antimonides RE_6Ge_(5-x)Sb-(11+x)(RE=La-Nd,Sm,Gd-Dy).All are metallic,with the members containing RE =Ce other than La displaying kinks in their resistivity vs temperature curves;the Tb and Dy members exhibit Kondo-like behavior with resistivity minima occurring at 10 and 150K,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<=22K.At 2K,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=5.75T.The single-crystal magnetoresistance of the Gd member below T_N 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.