Design, structural evolution, and radiation attenuation behavior of HfO₂-Modified ceramics

This study investigates the effects of doping HfO₂ (hafnium oxide) on Al₂Si₂O₅(OH)₄-KAlSi₃O₈-SiO₂ ceramics, fabricated via conventional firing and sintering, for photon and neutron shielding applications. Experimental measurements were performed using a¹³³Ba source for gamma shielding and a²⁴¹Am/Be neutron source for neutron shielding. At 81 keV gamma energy, the radiation attenuation properties of Hf0 (undoped) and Hf5 (doped, containing 30 % HfO₂) ceramics showed an increase in the mass attenuation coefficient from 0.180 to 1.812 cm²/g and in the linear attenuation coefficient from 0.417 to 5.799 cm^-1, while the mean free path (mfp) decreased from 2.398 to 0.172 cm, indicating a clear compositional dependence. Theoretical calculations were carried out using the EpiXS program. Among the produced ceramics, the Hf5 sample exhibited the highest neutron absorption rate, reaching 59.31 %. This work presents an innovative approach for developing HfO₂-doped ceramics for radiation-shielding applications. Compared to undoped systems, the incorporation of HfO₂ significantly enhances both gamma- and neutron-attenuation capabilities. The results demonstrate that HfO₂-doped ceramics constitute sustainable, cost-effective, and efficient alternatives for radiation protection in nuclear facilities, medical imaging technologies, and space applications.