The nature of the ³P₀ fluorescence quenching processes in LaF₃: Pr³⁺

The temporal decay profiles of ³P₀ fluorescence from five single crystals of LaF₃ with Pr³⁺ dopant concentrations from 1% to 80% have been measured at 2 K. The quenching of fluorescence from this level is discussed in terms of both long-range multipolar and short-range superexchange cross-relaxation interactions. The superexchange interaction provides the most consistent fit to the observed data and is believed to be dominant, however it is concluded that no single interaction provides a complete description of the fluorescence decay.