Computer modelling of the reduction of rare earth dopants in barium aluminate

Long lasting phosphorescence in barium aluminates can be achieved by doping with rare earth ions in divalent charge states. The rare earth ions are initially in a trivalent charge state, but are reduced to a divalent charge state before being doped into the material. In this paper, the reduction of trivalent rare earth ions in the BaAl2O4 lattice is studied by computer simulation, with the energetics of the whole reduction and doping process being modelled by two methods, one based on single ion doping and one which allows dopant concentrations to be taken into account. A range of different reduction schemes are considered and the most energetically favourable schemes identified.

The doping and subsequent reduction of a rare earth ion into the barium aluminate lattice.Figure optionsDownload as PowerPoint slideHighlights
► The doping of barium aluminate with rare earth ions reduced in a range of atmospheres has been modelled.
► The overall solution energy for the doping process for each ion in each reducing atmosphere is calculated using two methods.
► The lowest energy reduction process is predicted and compared with experimental results.