Thermographic properties of a Eu3+-doped (Y0.75Gd0.25)2O3 nanophosphor under UV and x-ray excitation

Phosphors are thermographic if their emission characteristics change with temperature. In this paper, we investigated the potential use of a europium-doped (1, 3 and 6 at.% Eu3+) yttrium–gadolinium oxide (Y0.75Gd0.25)2O3 nanostructured matrix for phosphor thermometry and thermometry in high-energy radiation fields. Photoluminescence emission measurements were recorded in the temperature range from room temperature to 873 K, observing temperature changes in trivalent europium ion transitions from 5D1 and 5D0 energy levels. The results show that Eu3+-doped (Y0.75Gd0.25)2O3 is a new promising high-temperature thermometric phosphor with a very good sensitivity of approximately 4.9 × 10−3 K−1 at 823 K for a sample doped with 1 at.% Eu3+. It is shown that with this material the fluorescence intensity ratio method can be used for temperature measurements in high-energy radiation fields without the use of an optical excitation source. In this case a maximal sensitivity of 2.35 × 10−3 K−1 is obtained. (paper)