Abstract
Superconducting and antiferroquadrupolar (AFQ) transitions in a Pr-based compound PrRhZn have been found to occur simultaneously at 0.06 K. The superconducting transition manifests itself by zero resistance and large diamagnetic susceptibility. The specific heat exhibits a Schottky anomaly peaking at 14 K, and magnetization curves measured at 2 K show anisotropic behaviors. The analysis of these data indicates that the crystalline electric field ground state of the trivalent Pr ion is the non-Kramers doublet with the quadrupolar degrees of freedom. A sharp peak in the specific heat at 0.06 K has been attributed not to the superconducting transition but to the AFQ transition because the ordering temperature decreases in [100] but increases in [110] and [111] with increasing up to 6 T. This anisotropic behavior of () can be well explained by a two-sublattice mean-field calculation, which corroborates the AFQ ordered state below . The entropy release at is only 10 of ln 2 expected for the doublet, suggesting possible interplay between the quadrupolar degrees of freedom and the superconductivity.
- Received 20 August 2012
DOI:https://doi.org/10.1103/PhysRevB.86.184426
©2012 American Physical Society