We present a systematic 115In NQR study on the heavy-fermion compounds CeRh1-xIrxIn5 (x=0.25, 0.35, 0.45, 0.5, 0.55, and 0.75). The results provide strong evidence for the microscopic coexistence of antiferromagnetic (AF) order and superconductivity (SC) in the range of 0.35≤x≤0.55. Specifically, for x=0.5, TN is observed at 3 K with a subsequent onset of superconductivity at Tc=0.9 K. Tc reaches a maximum (0.94 K) at x=0.45 where TN is found to be the highest (4.0 K). Detailed analysis of the measured spectra indicate that the same electrons participate in both SC and AF order. The nuclear spin-lattice relaxation rate 1/T1 shows a broad peak at TN and follows a T3 variation below Tc, the latter property indicating unconventional SC as in CeIrIn5 (Tc=0.4 K). We further find that, in the coexistence region, the T3 dependence of 1/T1 is replaced by a T-linear variation below T ∼0.4 K, with the value (T1)Tc/(T1)low T increasing with decreasing x, likely due to low-lying magnetic excitations associated with the coexisting magnetism.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - Jul 2004|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics