Fabrication of Gd2O2S:Tb scintillation ceramics using water-bath method: The influence of initial reaction temperature.

Gd 2 O 2 S:Tb nanopowders were synthesized in hot water-bath with the equal mole ratio of Gd 2 O 3 and H 2 SO 4 as raw materials. The influence of initial bathing temperature of Gd 2 O 3 and H 2 SO 4 , which was defined as initial temperature, on the properties of precursors and powders was investigated. The precursors and Gd 2 O 2 S:Tb powders showed a layered structure, and all the reduced powders exhibit a pure Gd 2 O 2 S phase. With the increase of the initial temperature, the size and thickness of the flakes in the precursors and Gd 2 O 2 S:Tb powders increased. Using the obtained powders as starting materials, Gd 2 O 2 S:Tb scintillation ceramics were successfully fabricated by vacuum pre-sintering at 1250 °C for 3 h, followed by HIP post-treatment at 1450 °C for 3 h. The Gd 2 O 2 S:Tb ceramics from the powders prepared at lower initial temperature show a rapid densification rate during pre-sintering. The Gd 2 O 2 S:Tb ceramics from powders synthesized at 7 °C show the highest optical transmittance and XEL intensity, and the total transmittance of the ceramics with the thickness of 1.0 mm is 25.5% at 545 nm. The microstructures of the Gd 2 O 2 S:Tb ceramics from powders synthesized at different initial temperatures were also studied. • Gd 2 O 2 S:Tb powders prepared at water-bath temperature of 7 °C exhibit the thinnest flake. • Gd 2 O 2 S:Tb ceramics were fabricated by vacuum pre-sintering and HIP post-treatment. • The total transmittance of Gd 2 O 2 S:Tb ceramics from the powders prepared at 7 °C reaches 25.5% at 545 nm. [ABSTRACT FROM AUTHOR]