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 longterm behavior of IPG during the underground disposal of high-level waste, and provides fundamental data to optimize the design of IPG formulations.