Composition dependence of Pr3+ spectral characteristics in strontium lanthanum aluminate crystals

An analysis of the high resolution spectra of the Pr3+ in strontium lanthanum aluminates, charge compensated with magnesium Sr1−xPryLax−yMgxAl12−xO19, (on a large composition range) is presented. The spectra are mainly dependent on the composition parameter x, and show more Pr3+ centers, two of them stable. Based on composition dependence and polarization data, structural models for the main two centers are proposed.