Low-temperature anomalies in magnetic, transport, and thermal properties of single-crystal CeRhSn with valence fluctuations

Magnetic, transport, thermal, and crystallographic properties are reported for single crystals of CeRhSn crystallizing in the hexagonal ZrNiAl-type structure. We found high anisotropy in both electrical resistivity (ρ_a≈5ρ_c at 70 K) and magnetic susceptibility (χ_c≈10χ_a at 0.4 K), which is atypical for a valence-fluctuating Ce compound. At low temperatures, ρ(T) and χ(T) show power-law behaviors; ρ_a(T)∝T^1.5 and ρ_c(T)∝T, and χ_a∝T^−0.35 and χc∝T^−1.1 down to 0.4 K. These behaviors and the rather large residual resistivity were not affected by long-term annealing. On cooling from 7 K to 0.5 K, the specific heat divided by temperature C/T increased as -ln T and saturated to a rather large value of 0.2 J/mol K². These experimental results are discussed in relation to the possible atomic disorder.