Temperature-sensitive properties of Y2Ti2O7: Pr3+, Tb3+ phosphors

Abstract

Y2Ti2O7: x% Pr3+, 5% Tb3+ (x = 0.3, 0.5, 1) phosphors were prepared by hydrothermal method with urea as precipitant. X-ray diffraction analysis results showed that the prepared samples presented face-centered cubic pyrochlore structure. From the field emission scanning electron microscope (FE-SEM) pictures, the morphology of the samples was irregularly spherical. The experiments showed that the different luminous thermal quenching trends of Pr3+ (1D2-3H4) and Tb3+ (5D4-7F5) and the fluorescence intensity ratio (FIR) of Pr3+ to Tb3+ varied significantly with temperature, which makes the samples available to describe temperature in 293–373 K. The relative sensitivity of Y2Ti2O7: 1% Pr3+, 5% Tb3+ sample remained above 2.5% K−1 in the tested temperature range during the experiment and reached a maximum of 3.04% K−1 at 314 K. The sample not only achieved a higher relative sensitivity maximum, but also maintained a quite high relative sensitivity within the experimental temperature range, and the value of the relative sensitivity (1% Pr3+, 5% Tb3+) reached more than 3.02% K−1 in the range of human body temperature (308–315 K). In addition, the temperature cycling tests of the sample displayed excellent repeatability in FIR temperature measurements. In conclusion, Y2Ti2O7: Pr3+, Tb3+ materials present good application prospects in the field of optical temperature sensors.