Crystal growth and evaluating luminescent properties of Eu-doped (Y, Lu, Sc)2O3 for optical thermometry

Optical thermometry is one of the promising methods of detecting temperature under harsh environments. In this study, for the development of a novel optical thermometer, we focused on Eu-doped (Y, Lu, Sc) 2 O 3 and grew single crystals using the micro-pulling-down method. Crystal growth was performed by systematically changing the ratio of Y to Lu, and the crystalline system and space group were identified to be cubic and Ia –3, respectively, by the powder X-ray diffraction analysis. From the photoluminescence emission spectra, the emission peaks attributed to Eu 3+ 5 D 0 – 7 F 1 and 5 D 1 – 7 F 1 transitions were observed. The temperature dependence of these emission peaks was measured and evaluated using the fluorescence intensity ratio method to estimate the performance as the optical thermometer. It was found that Eu-doped (Y, Lu, Sc) 2 O 3 can be used as the optical thermometer in the temperature range from 430 K to 790 K. The relative sensitivity reached a maximum of 0.22 %K −1 at 760 K. • Eu-doped (Y, Lu, Sc) 2 O 3 single crystals were grown by micro-pulling-down method. • The crystalline system and space group were identified to be cubic and Ia– 3. • Luminescence originating from Eu 3+ 5 D 0 – 7 F 1 and 5 D 1 – 7 F 1 transitions were observed. • The relative sensitivity for optical thermometer reached 0.22 % K −1 at 760 K.