First-principles calculation of the electric field gradient and magnetic hyperfine field in rare-earth metals (Gd to Lu) and dilute alloys with Cd

We present detailed ab initio calculations of the magnetic hyperfine field (B-hf) and electric field gradient (EFG) of a dilute Cd impurity in heavy rare-earth (RE) metals (Gd to Lu) using the GGA + U formalism of density functional theory (DFT). The calculated results closely agree with the experimental data available, allowing a quantitative understanding of hyperfine fields in rare-earth metals and alloys. In addition, we have estimated the impurity-induced perturbation to the host moment, and we find that the magnetic hyperfine field at a Cd impurity in RE metals scales with the spin moment of the nearest-neighbor (nn) RE atoms. The present work provides an improved understanding of B-hf at a Cd impurity in rare-earth hosts without the requirement of an orbital contribution as speculated earlier. (C) 2010 Elsevier Ltd. All rights reserved.