Emission lifetimes of europium-doped pyrochlores for phosphor thermometry

The luminescent lifetime of La2Zr2O7 and La2Hf2O7 has been determined as a function of temperature. We have shown that the luminescence of both materials can be used to determine the temperature of a surface up to 1073K. The results are qualitatively explained via multiphonon emission. Phonon energies and the number of phonons needed to cross the energy gap are estimated. The results are useful in the design of phosphors for noncontact thermometry in high-temperature applications.