Pressure-induced transition from a canted antiferromagnetic state to a ferromagnetic state in YbRhSb

Abstract

YbRhSb undergoes a transition at TM1 = 2.7 K into a canted antiferromagnetic state with a small spontaneous moment of 3 × 10−3 μB/Yb. With increasing pressure P, TM1(P) has a deep minimum of 2.5 K at 1.7 GPa. We have studied the pressure effect on the magnetization, resistivity and specific heat of a single crystal. With increasing pressure, the Kondo temperature estimated from the magnetic entropy decreases rapidly with increasing pressure, but remains at a constant value above 1.5 GPa. For P ≥ 2 GPa, the canted antiferromagnetic structure changes to a ferromagnetic one with a large moment 0.4 μB/Yb lying in the orthorhombic b − c plane. A metamagnetic behavior at B || a = 1.5 T remains in the ferromagnetic state. It is ascribed to the competition between the single-ion crystalline electric field anisotropy with easy direction || a and the inter-site exchange interaction with easy b − c plane.