Microstructure and Optical Properties of BaF$_2$ Transparent Ceramics Fabricated by Air Pre-sintering and Hot Isostatic Pressing

Le résumé fourni par la source

BaF$_2$ scintillation ceramics feature a rapid temporal response, high fast-component light yield, and a short X-ray attenuation length, making them a promising material for ultrafast X-ray imaging. In this work, BaF$_2$ nanopowder was co-precipitated from Ba(NO$_3$)$_2$ and KF$\cdot$2H$_2$O, consolidated by 600-750$^{\circ}$C air pre-sintering, and post-treated by hot isostatic pressing (HIP). The ceramics obtained under various process parameters allowed us to investigate temperature-dependent changes in microstructure, transmittance, and scintillation properties, including X-ray-excited luminescence (XEL), decay kinetics, and light yield. It was found that air pre-sintered compacts are porous, with relative density reaching a maximum at 700$^{\circ}$C. In addition, HIP eliminated most of the pores, leaving only residual intragranular pores. Both in-line transmittance and scintillation properties correlated strongly with increasing air pre-sintering temperature. The optimized BaF$_2$ ceramic achieves an in-line transmittance (1mm thick) of 57.6% and 40.6% at 800nm and 220nm, respectively, with a fast component of 16.8% and a light yield of 2655ph/MeV. High-temperature thermoluminescence suggests that a deep trap with considerable intensity may be responsible for the reduced light yield in the ceramic sample.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.