Unusual intrinsic thermoluminescence in LiMgPO<sub>4</sub>:Er
Д. Г. Келлерман, M.O. Kalinkin, R. M. Αbashev, N. I. Medvedeva, Α. I. Surdo, А. P. Tyutyunnik
Abstract
Olivine-type phosphate LiMgPO4 doped with rare-earth elements is currently considered as a new dosimetric material suitable for both OSL and TSL applications and able to compete with top commercial detectors. In this work, the samples of LiMgPO4:Er3+ were synthesized by the conventional solid state reaction method. We first studied X-ray luminescence and thermally and optically stimulated luminescence in LiMgPO4:Er3+ in detail. Our studies included the structure refinement, DFT calculations, which predicted the preferred positions of both erbium and charge-compensating vacancies, and UV-vis spectroscopy. We showed that the thermoluminescence spectrum of irradiated LiMgPO4:Er3+ does not contain components caused by the 4f-4f transitions in erbium, but coincides with the spectrum of the phosphate matrix with two broad bands at 360 nm and 650 nm. We discovered a high OSL and TSL output in LiMgPO4:Er3+, despite the nonradiative deexcitation of erbium ions.