Cd in SnO: probing structural effects through the electric-field gradient at the Cd-nucleus

LEONARDO ANTONIO ERRICO, MARIO RENTERIA, HELENA H. PETRILLI

San Pablo, Brasil,

Workshop; 13th Brazilian Workshop of Semiconductors Physics; 2007

USP, Brasil.

We perform an ab initio study of the electric-field gradient tensor at the nucleus (EFG) of Cd impurities at substitutional Sn sites in crystalline SnO. The Full-Potential Linearized-Augmented Plane Waves (FPLAPW) and the Projector Augmented Waves (PAW) methods used here allow us to treat the electronic structure of the doped system and the atomic relaxations introduced by the impurities in the host in a fully self-consistent way using a super-cell approach in a state-of-the-art way. Effects of the charge-state of the impurity on the electronic and structural properties are also discussed. We show that the structural effects induced by the defect play afundamental role in the understanding of the local electronic structure of this system. Since the EFG is a very subtle quantity, its determination is very useful to probe ground state properties like the charge density. Our theoretical predictions are compared with experimental results for the EFG at Cd sites in SnO inferred from Time-Diferential Perturbed-Angular-Correlations (PAC) experiments.