Single Crystal Study of PrRhIn5

The magnetization, specific heat and electrical resistivity of PrRhIn5 compound were studied. High quality crystals of PrRhIn5 and LaRhIn5, which adopt the tetragonal HoCoGa5-type (P4/mmm) structure, were prepared by solution growth. In the range 150 320 K the susceptibility χ follows the Curie-Weiss law. For PrRhIn5 the effective moment μeff and paramagnetic Curie temperature θp are μeff = 3. 7 μB/f.u. and θp = 28 K for B||c, μeff = 3.7 μB/f.u. and θp = -86 K for B||a. The values of the effective moments are near the value calculated for the free Pr ion (3.58 μB). The large difference of the values of the paramagnetic Curie temperature θp determined for the two principal crystallographic directions and the strongly anisotropic nonlinear 1/χ vs. T plots below 150 K are apparently the result of strong crystal field interaction, which yields a singlet ground state and a considerable gap between the ground state and the first excited state. Consequently, this material shows no magnetic ordering down to the lowest temperatures, where the van Vleck paramagnetism behavior is observed. In specific heat data an anomaly after applying field was found.