Fine-grained Ce, Y: SrHfO3 Scintillation Ceramics Fabricated by Hot Isostatic Pressing

Abstract

Ce: SrHfO3 ceramics possess a strong stopping power to high-energy rays due to their high density and high effective atomic number. However, it is difficult to obtain transparent Ce: SrHfO3 ceramics via traditional sintering method because of its orthogonal structure. In this work, Ce, Y: SrHfO3 ceramics were prepared by long-time vacuum sintering and short-time vacuum pre-sintering combined with hot isostatic pressing (HIP). The Ce, Y: SrHfO3 powders with a pure phase and a mean particle size of 152 nm were prepared by calcining at 1200 ℃ for 8 h using metal oxides and carbonates. The Ce, Y: SrHfO3 ceramics vacuum-sintered at 1800 ℃ for 20 h are opaque with an average grain size of 28.6 μm, while those prepared by the two-step sintering method show good optical transmittance. The evolution of the microstructure in the process of densification was analyzed in detail, and the influence of the pre-sintering temperature on the density, microstructure and optical transparency of Ce, Y: SrHfO3 ceramics was studied. The Ce, Y: SrHfO3 ceramics pre-sintered at 1500 ℃ for 2 h with HIP post-treatment at 1800 ℃ for 3 h have the highest in-line transmittance of 21.6% at 800 nm with a far smaller average grain size of 3.4 μm. Under X-ray excitation, the Ce3+ 5d-4f emission of Ce, Y: SrHfO3 ceramics was observed at 400 nm, and the XEL integral intensity is 3.3 times higher than that of Bi4Ce3O12 (BGO) crystals. The light yield of the Ce, Y: SrHfO3 ceramics is approximately 3700 ph/MeV with the shaping time of 1 μs. Good optical quality and scintillation performance of Ce, Y: SrHfO3 ceramics may expand the application range and potential in the field of scintillation detection.