High-Field Magnetization and Magnetoresistance of Single-Crystal CeRhSb

Abstract

We report the high-field magnetization and longitudinal magnetoresistance measurements in magnetic fields of up to 55 T, and Hall resistivity and transverse magnetoresistance measurements in fields of up to 15 T for single crystals of CeRhSb with a pseudogap in the density of states. The magnetization at 1.3 K shows rather weak anisotropy along the orthorhombic principal axes, Ma ≃ Mb > Mc, and the initial straight lines deviate upward near magnetic field values of 20, 30 and 25 T, respectively. The longitudinal magnetoresistance at 1.3 K is largely negative for both B//a and B//b and saturates near 30 T, while that for B//c is positive. The transverse magnetoresistance is positive and increases in proportion to B1.5 for B//c, while those for B//a and B//b saturate at around 10 T. The Hall coefficient for B//a changes sign from positive to negative below 4 K, while that for B//c progressively increases with decreasing temperature. The Hall resistivity for B//a and B//b possesses, respectively, negative and positive extrema at 10 T, whereas that for B//c increases linearly with B. These results indicate that the pseudogap in CeRhSb is suppressed for fields B//a and B//b above 10 T and almost disappears near 30 T, while it is hardly affected for B//c. This anisotropic field effect is markedly different from that of the isostructural Kondo semimetal CeNiSn, the pseudogap of which collapses in fields above 15 T only for B//a.