Luminescence sensing of temperature in pyrochlore zirconate materials for thermal barrier coatings

Pyrochlore zirconates are alternative materials to the presently used yttria-stabilized zirconia (7YSZ) for thermal barrier coatings. In this work, the use of europium as a solid-solution chromophore dopant is explored for measuring temperature in pyrochlore zirconates. Europium doping is found to give rise to strong luminescence as well as characteristic temperature-dependent luminescence lifetimes at high temperatures. Measurements of the luminescence lifetime of Eu-doped Gd2Zr2O7 and Eu2Zr2O7 pyrochlores, as well as Eu-doped YSZ, indicate sensitivity to temperature up to at least 1200 °C. The maximum temperature for Eu-doped Sm2Zr2O7 is lower, about 1000 °C, for the dopant concentration used. These measurements provide the basis for non-contact sensing of temperature in europium-doped pyrochlores used in coatings.