The spin-lattice relaxation rates (1 / T1) 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 / T1 shows the constant behavior of (T1 T)- 1 = 0.495 ± 0.002(s K)- 1 . On the other hand, in PuRhGa5, 1 / T1 is much larger than in LuCoGa5 and the 1 / T1 ∝ T behavior below ∼ 30 K is seen, where its (T1 T)- 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 ∼ 30 K in PuRhGa5.
- Relaxation rates