A new potential for radiation studies of borosilicate glass

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS

卷:393

Article; Proceedings Paper

Alharbi, Amal F.¹  Jolley, Kenny¹  Smith, Roger¹  Archer, Andrew J.¹  Christie, Jamieson K.² 

[1] Univ Loughborough, Dept Math Sci, Loughborough LE11 3TU, Leics, England

[2] Univ Loughborough, Dept Mat, Loughborough LE11 3TU, Leics, England

关键词: Molecular dynamics;    Borosilicate glass;    Interatomic potentials;   

DOI  :  10.1016/j.nimb.2016.12.007

来源: Elsevier

【 摘 要 】

Borosilicate glass containing 70 mol% SiO2 and 30 mol% B2O3 is investigated theoretically using fixed charge potentials. An existing potential parameterisation for borosilicate glass is found to give good agreement for the bond angle and bond length distributions compared to experimental values but the optimal density is 30% higher than experiment. Therefore the potential parameters are refitted to give an optimal density of 2.1 g/cm(3), in line with experiment. To determine the optimal density, a series of random initial structures are quenched at a rate of 5 x 10(12) K/s using constant volume molecular dynamics. An average of 10 such quenches is carried out for each fixed volume. For each quenched structure, the bond angles, bond lengths, mechanical properties and melting points are determined. The new parameterisation is found to give the density, bond angles, bond lengths and Young's modulus comparable with experimental data, however, the melting points and Poisson's ratio are higher than the reported experimental values. The displacement energy thresholds are computed to be similar to those determined with the earlier parameterisation, which is lower than those for ionic crystalline materials. (C) 2016 Elsevier B.V. All rights reserved.

【 授权许可】

Free