论文标题
由原子模拟驱动的配对分布功能分析：应用于微波辐射合成的Tio $ _2 $和ZRO $ _2 $
Pair distribution function analysis driven by atomistic simulations: Application to microwave radiation synthesized TiO$_2$ and ZrO$_2$
论文作者
论文摘要
提出了使用原子模拟产生的结构对缺陷材料进行对分布函数（PDF）分析的工作流程。大量的结构在存在的缺陷的类型和浓度上不同，是通过具有经验的原子间潜力来最小化的。每个结构都针对实验性PDF进行了完善。 fit $ r_w $值最低的结构被视为代表实验结构。该工作流程应用于二氧化钛钛（$ a-tio $ _2 $）和四方二氧化锆（$ t $ -t $ -ZRO $ _2 $），在存在微波辐射的情况下，这是一种产生障碍的低温过程。结果表明，钛空缺和间隙是$ a $ -tio $ _2 $中的主要缺陷，而氧气空缺则以$ t $ -ZRO $ _2 $为主导。从PDF细化中提取的原子位移参数和根据分子动力学模拟计算出的平方平方位移的分析表明，尽管这两个量密切相关，但在它们之间进行定量比较是一项挑战。工作流程可以应用于其他材料系统，包括纳米颗粒。
A workflow is presented for performing pair distribution function (PDF) analysis of defected materials using structures generated from atomistic simulations. A large collection of structures, which differ in the types and concentrations of defects present, are obtained through energy minimization with an empirical interatomic potential. Each of the structures is refined against an experimental PDF. The structures with the lowest goodness of fit $R_w$ values are taken as being representative of the experimental structure. The workflow is applied to anatase titanium dioxide ($a$-TiO$_2$) and tetragonal zirconium dioxide ($t$-ZrO$_2$) synthesized in the presence of microwave radiation, a low temperature process that generates disorder. The results suggest that titanium vacancies and interstitials are the dominant defects in $a$-TiO$_2$, while oxygen vacancies dominate in $t$-ZrO$_2$. Analysis of the atomic displacement parameters extracted from the PDF refinement and mean squared displacements calculated from molecular dynamics simulations indicate that while these two quantities are closely related, it is challenging to make quantitative comparisons between them. The workflow can be applied to other materials systems, including nanoparticles.
