Decolorization, spectral broadening, and luminescence enhancement in Tb:YO transparent ceramics through vacuum thermal reduction.

Tb is extensively employed in magneto-optical devices and luminescent materials owing to its distinctive physical properties. However, under certain conditions, trivalent Tb readily undergoes oxidation to tetravalent Tb, significantly reducing the performance of devices containing Tb. In this Letter, we report a technique called dual-annealing (DA) post-treatment, which effectively solves Tb oxidation issues by utilizing the reducibility of the vacuum environment. High-quality Tb:YO transparent ceramics were prepared with in-line transmittance of ∼80% at 800 nm. Subsequently, the prepared ceramics were subjected to DA treatment. The optical, photoluminescence, radioluminescence, and x-ray imaging properties of DA samples were comprehensively compared with those of conventionally single-annealed (SA) samples. The coloration of Tb:YO transparent ceramics due to Tb absorption was eliminated by DA. Notably, the DA sample showed a 3.28-fold increase in photoluminescence intensity and a 2.73-fold increase in radioluminescence intensity compared with the traditional SA sample. DA post-treatment enables Tb: YO transparent ceramics to achieve x-ray imaging capabilities. This Letter presents a simple, efficient, and universally applicable post-treatment technique expected to replace conventional hydrogen annealing in numerous scenarios.