Iron phosphate glasses: Structure determination and displacement energy thresholds, using a fixed charge potential model
Iron phosphate glasses: Structure determination and displacement energy thresholds, using a fixed charge potential model
复制标题
DOI：
10.1016/j.jnoncrysol.2014.12.033
复制
发表时间：
2015-03-01
影响因子：
3.5
通讯作者：
Smith, Roger
中科院分区：
文献类型：
--
作者：
Joseph, Kitheri;Jolley, Kenny;Smith, Roger
磷酸铁玻璃是一种多用途的基质，用于固定高放射性核废料（HLW）中的各种放射性元素。淬火玻璃结构的铁磷酸盐玻璃的Fe/P比为0.33，0.67和0.75，并与40摩尔%的Fe 2 O3和60摩尔%的P2 O 5的组成，与4%和17%的Fe 2+离子浓度产生使用分子动力学和阈值位移能计算。在最低能量结构中，我们发现在几乎所有的情况下，P原子是4重配位的。每个原子的势能随着Fe 2+离子浓度的增加而增加，具有相似的Fe/P比，这表明降低Fe 2+含量是一个稳定因素。计算出Fe ~（2+）-O、Fe ~（3+）-O、P-O和O-O之间的平均键距分别为2.12、1.88、1.5和2.5埃。的阈值位移能（E-d）被认为是依赖于离子种类，Fe 2+离子相比，Fe 3+离子，总体上略低于硼硅酸盐玻璃确定。(C)2015年，作者。由爱思唯尔公司出版
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 angstrom respectively. The threshold displacement energy (E-d) 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. (C) 2015 The Authors. Published by Elsevier B.V.