Luminescence of Pr3+ Impurity Centers and Defects in Sr9Sc (PO4)7:Pr3+

The spectroscopic characteristics and luminescence decay kinetics of Sr9Sc(PO4)(7):Pr3+(1%) were investigated using synchrotron radiation of ultraviolet (UV), vacuum ultraviolet (VUV) and X-ray ranges, as well as pulsed cathodoluminescence (PCL) methods at temperatures of 10, 90, and 295 K. The luminescence spectra contain three groups of bands and lines. In the UV range, the observed bands correspond to interconfigurational 5d 4f transitions in Pr3+ ions. In the visible spectrum, the wide luminescence band of defects dominates, as well as narrow lines associated with intraconfigurational 4f 4f transitions in Pr3+ ions. When excited by an electron beam (5 Hz), the main component with a decay time approximate to 17 ns dominates in the decay kinetics of the 5d 4f luminescence. The decay kinetics of 5d 4f luminescence upon excitation with high-frequency ( approximate to 8 MHz) synchrotron radiation of the X-ray range contains a fast component ( approximate to 15 ns) against the background of the slow component of the s-range. An effective nonradiative energy transfer is observed from impurity centers to defects, as well as from the host to Pr3+ ions and defects.