Eu3+ doped Gd2Ti2O7 nanoparticles as a luminescence thermometry probes

This chapter analyzes the potential of Eu³⁺ doped Gd₂Ti₂O₇ nanopowders for the luminescence thermometry. Gd₂Ti₂O₇ powders doped with 5 at% Eu³⁺ ions were prepared using Pechini-type polymerized complex route. Phosphor thermometry represents an optical technique for surface temperature measurements. Temperature evolution can be remotely determined by measuring changes in the luminescent properties of the probe, such as absolute and relative emission intensities, lifetime values of excited states, peak position, and the emission bandwidth. Lifetime method is based on the determination of emission decays over the observed temperature range. With the increasing of temperature, lifetime decay decreases due to the thermal quenching effect so temperature is measurable only at the point and within a relatively limited range. Small changes in trap emission intensities are a consequence of slight changes in optical properties of the host with temperature such as band gap energy, reflectivity and changes of experimental parameters during the measurements.