Optical properties of Pr and Eu-doped SrAl12O19: A theoretical study

This paper describes a computational study of extrinsic defect and optical properties of SrAl12O19 induced by trivalent rare earth dopants. Solution energies for a range of possible doping mechanisms are calculated, and predictions made of doping sites and charge-compensation schemes. Atomistic modelling is used to calculate the symmetry and detailed geometry of the dopant ion-host lattice system, and this information is then used to calculate the crystal field parameters. It is found that the preferred doping mechanism for Pr is a substitution at Sr2+ sites, with charge compensation by anti-site and for Eu is a substitution at the Al3+ site. Crystal field parameters have been calculated and the results discussed in terms of optical properties of the doped systems. B-q(k) values indicate that the site symmetry is D-2h. The transition levels are then calculated for the Pr3+ and Eu3+-substituted material, and comparisons made with experimental results have a good agreement. (C) 2015 Elsevier B.V. All rights reserved.