Enhancement of relaxation rates in the normal state of superconductor PuRhGa5:NQR relaxation study

The spin-lattice relaxation rates (1/T-1) have been measured under zero field using nuclear quadrupole resonance (NQR) lines in superconductor PuRhGa5 and Pauli-paramagnet LuCoGa5. In the reference LuCoGa5 with fully-occupied 4f shell, the 1/T-1 shows the constant behavior of (T1T)(-1) = 0.495 +/- 0.002 (s K)(-1). On the other hand, in PuRhGa5, 1/ T-1 is much larger than in LuCoGa5 and the 1/T-1 alpha T behavior below similar to 30 K is seen, where its (T1T)(-1) value is 3.27 +/- 0.005 (s K)(-1). These results suggest a development of coherent Fermi liquid state incorporated with 5f electrons below similar to 30K in PuRhGa5. (c) 2006 Elsevier B.V. All rights reserved.