Manganese is capable of exist in many oxidation states from +1 to +7. In research of phosphors especially attractive and intensively studied in last years is a d-d emissions from Mn²⁺ and Mn⁴⁺. In both cases the luminescence may appear in red spectral range, greatly attractive for WLEDs.¹ Yet, being strongly dependent on the host lattice the Mn²⁺ emission can vary from green to deep red with decay time in the order of ms.

This presentation is devoted to Mn²⁺ emission in cubic Lu₂O₃ host lattice which offer two nonequivalent site symmetry, C₂ and C_3i, for the dopant ion.² A successful technology of effective permanent stabilization of Mn²⁺ in this host will be presented.

The preliminary spectroscopic investigation showed that the title system is able to produce thermoluminescence after irradiation with X-rays or UV-rays. Furthermore, in PL measurements detected in wide temperature range the system is able to produce 2 or even 3 different emissions whose intensities change in a complex way. These observations tells to consider the possible usefulness of the system to serve as a prospective luminescence thermometer working over a broad range of temperatures.

This research was supported by Polish National Science Centre upon the grant #UMO-2017/25/B/ST5/00824.

1. Q. Zhou, L. Dolgov, A. M. Srivastava, L. Zhou, Z. Wang, J. Shi, M. D. Dramićanin, M. G. Brik and M. Wu, Mn²⁺ and Mn⁴⁺ red phosphors: Synthesis, luminescence and applications in WLEDs. A review, J. Mater. Chem. C, 2018, 6, 2652–2671.
2. E. Zych, Concentration Dependence of Energy Transfer between Eu³⁺ ions occupying two symmetry sites in Lu₂O₃, J. Phys. Condens. Matter, 2002, 14, 5637–5650.