A first-principle study of the site preference of Cd impurity in Hf-Ag and Zr-Ag compounds

A detailed theoretical study of the structure and electric field gradients (EFG) of the Hf2Ag, HfAg, Zr2Ag and ZrAg compounds is presented. Using all-electron augmented plane waves plus local orbitals (APW + lo) formalism, the equilibrium volumes and EFGs for the mentioned compounds are calculated. We have also performed supercell calculations with Cd and Ta impurities. Through the comparison of theoretical and experimental EFGs in these cases, we elucidate the role played by the Cd probe in the time-differential perturbed angular correlation (TDPAC) measurements of Hf-Ag and Zr-Ag compounds.