Effect of boron doping on the irradiation resistance of iron phosphate glass: Insights from mechanical properties and chemical stability

We investigated the ion-irradiation effects of iron phosphate glasses (IPGs) with composition of 40Fe₂O₃‒60P₂O₅ (mol%) and 10B₂O₃‒36Fe₂O₃‒54P₂O₅ (mol%), respectively, and explored the effect of boron doping on the mechanical properties and the chemical stability. Mono-ion irradiation (5-MeV Xe²⁰⁺) and sequential irradiation scenario (5-MeV Xe²⁰⁺+ 250-keV H⁺) were performed with different doses. As the Xe-dose increased, both the hardness and the Young's modulus decreased until converging to saturation, and then the hardness tended to recover. The variations in mechanical properties and water contact angle of the 10B₂O₃‒36Fe₂O₃‒54P₂O₅ were more significant than those of the 40Fe₂O₃‒60P₂O₅, indicating inferior irradiation resistance. The hardness recovery was also observed in H-ion irradiation whose energy deposition is predominated by electronic interaction, while the boron doping weakened this phenomenon. Our study contributes to understanding the long-term behavior of IPG during the underground disposal of high-level waste, and provides fundamental data to optimize the design of IPG formulations.