热等静压烧结制备细晶粒Ce,Y:SrHfO3闪烁陶瓷

Ce:SrHfO₃陶瓷因具有高密度和高有效原子序数, 对高能射线具有很强的阻止能力。同时, Ce:SrHfO₃陶瓷还具有快衰减和高能量分辨率等优异的闪烁性能, 引起了研究人员的广泛关注。由于传统的烧结方法难以实现非立方结构Ce:SrHfO₃陶瓷的透明化, 本研究采用真空长时烧结和短时真空预烧结合热等静压烧结(Hot Isostatic Pressing, HIP)方法制备Ce,Y:SrHfO₃陶瓷。以金属氧化物和碳酸盐为原料, 1200 ℃下煅烧8 h可以获得平均粒径为152 nm的纯相Ce,Y:SrHfO₃粉体。1800 ℃真空烧结20 h获得平均晶粒尺寸为28.6 μm的不透明的Ce,Y:SrHfO₃陶瓷, 而两步烧结法可以制备光学透过率良好的Ce,Y:SrHfO₃陶瓷。本研究详细分析了陶瓷致密化过程中微结构的演变, 探究了预烧结温度对Ce,Y:SrHfO₃陶瓷密度、显微结构和光学透过率的影响。真空预烧(1500 ℃×2 h)结合HIP后处理(1800 ℃×3 h, 200 MPa Ar)所获得的Ce,Y:SrHfO₃陶瓷在800 nm处的最高直线透过率为21.6%, 平均晶粒尺寸仅为3.4 μm。在X射线激发下, Ce,Y:SrHfO₃陶瓷在400 nm处产生Ce³⁺ 5d-4f发射峰, 其XEL积分强度比商用锗酸铋(BGO)晶体高3.3倍, Ce,Y:SrHfO₃陶瓷在1 μs门宽下的光产额约为3700 ph/MeV。良好的光学和闪烁性能可以拓宽Ce,Y:SrHfO₃陶瓷在闪烁探测领域的应用。

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

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.