Ab initio calculations of the EFG at Cd impurities in rutile SnO2

L. A. ERRICO; G. FABRICIUS; M. RENTERIA

Utah

Conferencia; 12th International Conference on Hyperfine Interactions; 2001

We report in this contribution an ab-initio study of the electric-field gradient (EFG) at Cd impurities located at the cation site in the semiconductor SnO2 (rutile phase). The study was performed with the WIEN97 implementation, developed by Blaha et al. [1], of the full-potential linearized-augmented-plane-wave (FP-LAPW) method. In this method no shape approximation on either the potential or the electronic charge density is made, being thus specially suited for EFG calculations. The importance of this kind of calculations, besides the theoretical interest of the problem (metallic impurities in oxides), is that the isotope 111Cd is one of the most popular tracer in perturbed-angular-correlation (PAC) experiments. In order to simulate the dilute Cd-impurity in the SnO2 host we use a 72-atoms super-cell and calculate the electronic structure of the system and forces on the atoms, studying the relaxation introduced by the impurity in the lattice. Finally, the obtained results are compared with experimental data [2] and previous calculations performed in rutile TiO2.