Fluorescence intensity ratio (FIR) analysis of the temperature sensing properties in transparent ferroelectric PMN-PT:Pr³⁺ ceramic

A transparent ferroelectric 0.75Pb(Mg1/3Nb2/3)O3-0.25PbTiO3:0.015Pr3+ ceramic was synthesized and its temperature-sensing ability was investigated based on the fluorescence intensity ratio (FIR) method. The transparency was found to be of the order of 68% at 900 nm for a sample thickness of 0.7 mm, comparable to the theoretical value of ~71%, benefiting the photoluminescence of the Pr3+ ions inside the ceramic. Instead of the traditional Boltzmann exponential style and varying sensitivity, a highly linear temperature response was obtained for the studied ceramic. Further, a constant FIR sensitivity of 0.70 %K-1 was achieved over the temperature range of -50–40 °C, making the ceramic suitable for thermometry at room temperature and below.