Self-diffusion in Sr-containing iron-polyphosphate glasses by molecular dynamics simulations - research data

Among many possible applications of iron-phosphate glasses, they are promising materials in waste vitrification with special attention to radioactive waste. In vitrified form, the waste elements should be permanently immobilized in the glass network and should be susceptible to harsh environmental conditions. The self-diffusion of the vitrified material species may limit the potential usefulness of the glasses. The paper presents the possibility of using molecular dynamics simulations to study the process and influence its SrO substitution into the iron-phosphate glass network. It was evidenced that the self-diffusion mechanism differs significantly if the glass is in a solid or liquid state. The proposed method gives also the possibility of relatively easy prediction of glass characteristics temperatures like transformation and flow. It also observed and described a process of aggregation of glass elements that may drive its crystallization. The obtained results are discussed in light of experimental and theoretical structural feature literature data.