EuF3/Ga2O3 Dual-Phase Nanostructural Glass Ceramics with Eu2+/Cr3+ Dual-Activator Luminescence for Self-Calibrated Optical Thermometry

To circumvent the requirement of small energy gap between thermally coupled levels of lanthanide probes in optical thermometry, a strategy using dual-activator fluorescence intensity ratio as temperature signal in dual-phase nanostructural glass ceramics was reported. Specifically, oxyfluoride glass with specially designed composition of SiO2-Al2O3-LiF-EuF3-Ga2O3-Cr2O3 was fabricated, and subsequently glass crystallization was used to induce homogeneous precipitation of hexagonal EuF3 and cubic Ga2O3 nanocrystals among the glass matrix. Impressively, Eu2+ activators were produced after glass crystallization in an air atmosphere, and the Cr3+ emitting center was evidenced to incorporate into Ga2O3 crystalline lattice. As a result, temperature determination with high sensitivity of 0.8% K-1, large energy gap of 8500 cm(-1), and superior thermal stability were realized by taking advantage of the fluorescence intensity ratio between Eu2+ and Cr3+ as detecting parameter, which exhibited a linear dependence on temperature. We believe that this preliminary investigation will provide a practical approach for developing a high-performance self-calibrated optical thermometer.