Non-contact thermometry with Dy3+ doped Gd2Ti2O7 nano-powders

The performance of Dy3+ doped Gd2Ti2O7 nano-powders for luminescence temperature sensing was tested over a temperature range from 293 to 443 K. The Dy3+ ions were incorporated into Gd2Ti2O7 nanocrystals using a hydrolytic sol-gel route. Microstructural characterization of the obtained material was performed using transmission electron microscopy and X-ray diffraction measurements. Luminescence spectra of Dy3+ doped Gd2Ti2O7 nano-powders consists of two distinct spectral regions: the high-energy region associated with the trap emission of the Gd2Ti2O7 host and the low-energy region with well-resolved emission peaks of the Dy3+ ions. The ratio between intensities of two Dy3+ emission lines, as well as the ratio between intensities of trap emission of host and Dy3+ emission show strong temperature dependence and are tested for temperature sensing. In both cases, ratiometric measurements provide comparable quality of temperature sensing, and when they are combined the relative sensor sensitivities were found to be higher than 0.9% K−1 over given temperature range. The fluorescence quenching of Dy3+ ions was discussed in terms of simple theoretical models.