Three-mode fluorescence thermometers based on double perovskite Ba2GdNbO6:Eu3+,Mn4+ phosphors

Herein, Ba2GdNbO6:Eu3+,Mn4+ phosphors with dual emission centers were manufactured as three-mode fluorescence thermometers. Their structure, micromorphology and luminescent properties were explained in-depth. Excited at 394 nm, the characteristic emission peaks of transitions of 5D0→7F of Eu3+ and 2Eg→4A2g of Mn4+ in Ba2GdNbO6:Eu3+,Mn4+ can be simultaneously detected. In addition, three-mode fluorescence thermometers with high sensitivity were developed, utilizing temperatures dependence of emission intensity (EI) of Mn4+, fluorescence intensity ratio (FIR) of Eu3+ and Mn4+, as well as fluorescence lifetime (FL) of 2Eg level of Mn4+. In EI, FIR and FL modes, the maximal relative sensitivities achieve 1.78 %K−1@423 K, 2.72 %K−1@483 K and 1.73 %K−1@430 K, respectively. The results indicate that Ba2GdNbO6:Eu3+,Mn4+ can be used as a candidate material for three-mode fluorescence thermometers.