Red emitting Ba2LaNbO6: Mn4+ phosphor for the lifetime-based optical thermometry

The Ba2LaNbO6: Mn4+ phosphor is synthesized through high-temperature solid-state method and characterized its crystal structure through X-ray powder diffraction. The value of Dq, the Racah parameters B and C, and the nephelauxetic effect parameter β1 of Ba2LaNbO6: Mn4+ have been calculated by its luminescent spectra. The temperature-dependent spectra of Mn4+ emission illustrated the thermal quenching of Ba2LaNbO6: Mn4+ phosphors. Additionally, the fluorescence lifetime-based optical temperature measurement value has been analyzed. According to the work, the maximum Sa value is 0.0024 msK-1 at 354 K and the maximum Sr is 2.77 %K-1 at 397 K. These results proved that the Ba2LaNbO6: Mn4+ phosphor has prospective potential in optical thermometry.