arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 0802.1300cond-mat.mtrl-sci
收藏

弛豫体积张量计算中的弹性效应

Elastic effects on relaxation volume tensor calculations

B. Puchala, M. L. Falk, K. Garikipati

摘要:

弛豫体积张量量化应力对晶体缺陷扩散的影响。连续体线性弹性预测,这些参数的计算使用周期性边界条件不遭受系统偏差,由于弹性图像效应,应该是独立的超胞大小或对称性。然而,在实践中,在Stillinger-Weber硅的间隙形成体积张量的计算<110>表明,在缺陷处的键合的变化影响的弹性模量,并导致系统的大小依赖的弛豫体积。这些随系统大小的倒数而变化。知道收敛速度允许从适度规模的计算中准确估计这些量。此外,在连续体线性弹性假设内,平均应力可用于从恒定体积计算估计松弛体积张量。

英文摘要:

Relaxation volume tensors quantify the effect of stress on diffusion of crystal defects. Continuum linear elasticity predicts that calculations of these parameters using periodic boundary conditions do not suffer from systematic deviations due to elastic image effects and should be independent of supercell size or symmetry. In practice, however, calculations of formation volume tensors of the <110> interstitial in Stillinger-Weber silicon demonstrate that changes in bonding at the defect affect the elastic moduli and result in system-size dependent relaxation volumes. These vary with the inverse of the system size. Knowing the rate of convergence permits accurate estimates of these quantities from modestly sized calculations. Furthermore, within the continuum linear elasticity assumptions the average stress can be used to estimate the relaxation volume tensor from constant volume calculations.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑