GaNQR relaxation rates in superconductor PuRhGa5

Nuclear quadupole resonance (NQR) measurements have been performed on the Pu-based superconductor PuRhGa5 with a transition temperature of similar to 8.8 K. NQR lines ascribed to Ga-69(2), Ga-71(2), and Ga-69(1) have been found in zero field. Spin-lattice relaxation rate (1/T-1) data for these lines have been measured in the superconducting state. The temperature variation of 1/T-1, can be interpreted in terms of a line-nodal superconducting gap. Data for both the Ga-69(2) and Ga-69(1) NQR lines show a constant-T1T behavior between T-c and T*similar to 30 K, which suggests that a coherent Fermi-liquid state sets in below T*. The modified Korringa relation using 1/T-1 and Knight shift data in an applied field indicates that the normal state of PuRhGa5 can be regarded as an antiferromagnetically correlated metal. (c) 2007 Elsevier Ltd. All rights reserved.