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 (rho(a)approximate to5rho(c) at 70 K) and magnetic susceptibility (chi(c)approximate to10chi(a) at 0.4 K), which is atypical for a valence-fluctuating Ce compound. At low temperatures, rho(T) and chi(T) show power-law behaviors; rho(a)(T)proportional toT(1.5) and rho(c)(T)proportional toT, and chi(a)proportional toT(-0.35) and chi(c)proportional toT(-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 K-2. These experimental results are discussed in relation to the possible atomic disorder.