Quantum criticality and development of antiferromagnetic order in the quasikagome Kondo lattice CeRh1−xPdxSn
AbstractCeRhSn with a quasikagome lattice of Ce atoms in the hexagonal c plane has been expected to be in close vicinity to a zero-field quantum criticality derived from magnetic frustration. We have studied how the ground state changes with substitution of Pd for Rh in CeRh1−xPdxSn (x≤0.75) by measuring the specific heat C, magnetic susceptibilities χdc and χac, magnetization M, electrical resistivity ρ, and magnetoresistance. For x=0, the field dependence of χac at T=0.03K shows a peak at B∥a=3.5T, confirming the spin-flop crossover in the field applied along the hard axis. The temperature dependence of χac shows a broad maximum at 0.1 K whereas C/T continues to increase down to 0.08 K. For x≧0.1,ρ(T) is dominated by incoherent Kondo scattering and both C/T and χac(T) exhibit peaks, indicating the development of an antiferromagnetic order. The ordering temperature rises to 2.5 K as x is increased to 0.75. Our results indicate that the ground state in the quasikagome Kondo lattice CeRh1−xPdxSn leaves the quantum critical point at x=0 with increasing x as a consequence of suppression of both the magnetic frustration and Kondo effect.