2134/16873 Kitheri Joseph Kitheri Joseph Kenny Jolley Kenny Jolley Roger Smith Roger Smith Iron phosphate glasses: structure determination and displacement energy thresholds, using a fixed charge potential model Loughborough University 2015 Computer simulation Displacement energy thresholds Iron phosphate glass Structure Mathematical Sciences not elsewhere classified Condensed Matter Physics 2015-03-04 12:43:22 Journal contribution https://repository.lboro.ac.uk/articles/journal_contribution/Iron_phosphate_glasses_structure_determination_and_displacement_energy_thresholds_using_a_fixed_charge_potential_model/9387392 Iron phosphate glass is a versatile matrix for the immobilisation of various radioactive elements found in high-level nuclear waste (HLW). Quenched glass structures of iron phosphate glasses with Fe/P ratios of 0.33, 0.67 and 0.75 and with a composition of 40 mol% Fe2O3 and 60 mol% P2O5, with 4% and 17% Fe2 + ion concentrations were generated using molecular dynamics and the threshold displacement energies calculated. In the minimum energy structures, we found that in nearly all cases the P atoms were 4-fold coordinated. The potential energy per atom increased with increasing concentration of Fe2 + ions with similar Fe/P ratio, suggesting that decreasing the Fe2 + content is a stabilising factor. The average bond distances between Fe2 +-O, Fe3 +-O, P-O and O-O were calculated as 2.12, 1.88, 1.5 and 2.5 Å respectively. The threshold displacement energy (Ed) was found to be dependent upon the ion specie, less for Fe2 + ions compared to Fe3 + ions, and was overall slightly lower than that determined for borosilicate glass.