LAUSR

Abstract In this work, the potential of Li 1 . 8 Na 0 . 2 TiO 3 : Mn 4 + for the lifetime-based luminescence thermometry is assessed. The material is prepared by the solid-state reaction of Li2CO3, Na2CO3, and nanostructured TiO2 at 800 °C, and its monoclinic structure (space group C2/c) is confirmed by X-ray diffraction analysis. In this host, Mn 4 + provides strong absorption around 330 nm and 500 nm due to 4A 2g →  4T 1g and 4A 2g →  4T 2g electric dipole forbidden and spin-allowed electron transitions, respectively, and emits around 679 nm on account of 2E g → 4A 2g spin forbidden electron transition. Temperature dependences of emission intensity and emission decay are measured over the 10–350 K range. Due to the low value of energy of 4T 2g level (20000 cm−1), the strong emission quenching starts at low-temperatures which favors the use of this material for the luminescence thermometry. It is demonstrated that the quite large value of relative sensitivity (2.27% K−1@330 K) facilitates temperature measurements with temperature resolution better than 0.15 K, and with the excellent repeatability.