Coexistence of antiferromagnetism and superconductivity in CeCo(In0.9Cd0.1)(5): A spin lattice relaxation study

Abstract

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 Neel temperature T-N = 2.8 K, with a subsequent onset of SC at T-c similar or equal to 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 T-i-component, which suggests a homogeneous nature of the Ce-4f(1) electronic state. (c) 2007 Elsevier B.V. All rights reserved.