Ab initio study of Cd-doped Sc2O3 semiconductor and comparison with 111Cd PAC experiments

E. MUÑOZ; D. RICHARD; L. A. ERRICO; M. RENTERÍA

Buenos Aires

Workshop; Workshop "At the Frontiers of Condensed Matter physics IV"; 2008

Comite internacional

The combination of hyperne techniques and theoretical simulations based on ab initio calculations has been shown to be a powerful tool to unravel structural characterizations in the atomic scale of impurities in solids. A recent example has been the study of SnO:Cd, where ab initio calculations [1] and Perturbed Angular Correlations (PAC) measurements were combined to describe the dynamic hyperne interactions observed at 111Cd impurities in the SnO semiconductor [2], originated in the electron-capture (EC) decay after-eects (AE) of the parent isotope 111In. In this work, we present an ab initio study on the Cd-doped Sc2O3 semiconductor that enables a description of the dynamic interactions observed in PAC experiments using 111In-implanted Sc2O3 samples. The theoretical study was performed at Cd impurities located at both cationic sites C and D of the Sc2O3 Bixbyite structure, using the Augmented Plane Waves + Local Orbital (APW+LO) method in the framework of the Density Functional Theory (DFT), with an impurity dilution of 1:48. We studied the EFGs for dierent charge states of the Cd impurity (neutral supercell and 1-electron added supercell). These theoretical results are compared with PAC results reported by Bartos et al. [3], in which an strong damping of the spin-rotation spectra was observed at low temperatures (lower than 600K). This damping is produced by dynamic hyperne interactions that were correlated with the EC decay AE of 111In probes. Our ab initio results are in excellent agreement with the experimental EFGs and can explain the origin of the dynamic interactions observed.