Er3+ doped ferroelectric Pb(Mg1/3Nb2/3)O3-0.25PbTiO3 ceramic used as a linear response fluorescent temperature sensor

Er3+ doped ferroelectric Pb(Mg1/3Nb2/3)O3-0.25PbTiO3 (PMN-PT) ceramic was grown by using a two-stage sintering method. The sample shows relatively strong upconversion (UC) visible fluorescence under a 980 nm diode laser excitation and the fluorescence spectra were recorded in the temperature (T) range of 300-600 K. The fluorescence intensity ratios (FIR) of different energy levels, like 2H11/2, 4S3/2, 4F9/2, and its stark sublevels, were studied as functions of temperature. The responses of FIR adopted here have a linear response to temperature in certain temperature range, and the resolutions achieved for temperature sensing using this material can be 0.5 K with the sensitivity as high as 2.9% K−1.