Structural evaluations and temperature dependent photoluminescence characterizations of Eu(3+)-activated SrZrO(3) hollow spheres for luminescence thermometry applications

This research is focused on the temperature sensing ability of perovskite SrZrO(3):Eu(3+) hollow spheres synthesized via the sol-gel method followed by heating. The Rietveld refinement indicated that the precursors annealed at 1100 °C were crystallized to form orthorhombic SrZrO(3). SrZrO(3) particles exhibited non-agglomerated hollow spherical morphology with an average particle size of 300 nm. The UV-excited photoluminescence spectrum of SrZrO(3):Eu(3+) consisted of two regions. One region was associated with SrZrO(3) trap emission, and the other one was related to the emission of Eu(3+) ions. The intensity ratio of the emission of Eu(3+) ions to the host emission (FIR) and the emission lifetime of Eu(3+) ions were measured in the temperature range of 300–550 K. The sensitivity obtained via the lifetime method was 7.3× lower than that measured via the FIR. Within the optimum temperature range of 300–460 K, the as-estimated sensor sensitivity was increased from 0.0013 to 0.028 K(−1). With a further increase in temperatures, the sensitivity started to decline. A maximum relative sensitivity was estimated to be 2.22%K(−1) at 460 K. The resolutions in both methods were below 1K in the above temperature range. The results indicated the suitability of SrZrO(3):Eu(3+) for the distinct high temperature sensing applications.