UC Irvine

We present an In(1) NQR study on the heavy-fermion (HF) compound CeCo(In1-xCdx)5(x = 0.10) . Bulk measurements indicate that Cd doping acts as an electronic tuning agent in CeCoIn5, and that superconductivity (SC) and antiferromagnetism (AFM) may coexist at ambient pressure for 0.05 < x < 0.15. For x = 0.10, the nuclear spin lattice relaxation rate shows a broad peak at the Néel temperature TN = 2.8 K, with a subsequent onset of SC at Tc ≃ 1.2 K. Our results provide strong evidence for microscopic coexistence of these two ground states. The nuclear magnetization recovery curves in both the ordered and mixed states reveal a single T1-component, which suggests a homogeneous nature of the Ce-4f1 electronic state. © 2007 Elsevier B.V. All rights reserved.