摘要
钙钛矿氧化物中的氧八面体旋转(Oxygen Octahedral Rotation,OOR)与其物性密切相关,近期同步辐射三维衍射技术的发展为高效表征氧八面体旋转对应的超晶格半指数峰提供了可能,但在定量分析方面仍有困难。理论上的计算模拟可以为半指数峰测量提供指引,并为其定量分析奠定基础。基于晶体衍射运动学基本理论,推导出比较普适的氧八面体旋转对应的半指数峰强度的定量计算公式;通过编写程序,模拟了27种旋转模式下的强度分布,并总结出对应的半指数峰出现规律;基于这些规律,可以预测或判定实验中半指数峰的来源;两种典型示例验证了模拟结果与实测结果相符。该工作将促进同步辐射衍射在钙钛矿氧八面体旋转表征中的应用。
[Background]The oxygen octahedral rotation(OOR)in perovskite oxides is closely related to its physical properties.The recent development of synchrotron radiation three-dimensional diffraction provides opportunities for efficient characterization of the superlattice half-order peaks corresponding to OOR,but quantitative analysis is still difficult.[Purpose]This study aims to provide guidance for the measurement of OOR half-order peaks and lay a foundation for their quantitative analysis through a theoretical simulation of the half-order peak intensity.[Methods]Firstly,a universal calculating formula for coordinates of all the oxygen ions in an OOR super cell was provided.Then,starting from the calculation formula of structure factor of a lattice unit cell,a quantitative formula for calculating the half-order peak intensity of lattice with OOR was deduced according to the basic theory of crystal diffraction kinematics.Subsequently,the half-order peak intensity distribution patterns corresponding to the 27 rotation modes were simulated and exhibited by programming,and the appearance rules were summarized.Finally,two typical examples were used to verify the consistency between the simulation results and the measured results.[Results&Conclusions]Two typical examples show that the simulation results are in good agreement with the measured results.Based on these results,the OOR half-order peak pattern can be predicted beforehand and their origins may be verified after hand for experimental measurement of half-order peak.This work may promote the application of synchrotron radiation diffraction in the characterization of perovskite OOR.
作者
陶亚军
董永齐
孙喆
罗震林
TAO Yajun;DONG Yongqi;SUN Zhe;LUO Zhenlin(National Synchrotron Radiation Laboratory,University of Science and Technology of China,Hefei 230026,China)
出处
《核技术》
北大核心
2025年第2期27-33,共7页
Nuclear Techniques
基金
国家自然科学基金(No.12175235,No.62271462)
国家重点研发计划(No.2022YFA1603902)资助。
关键词
钙钛矿氧化物
氧八面体旋转
半指数峰
同步辐射
三维衍射
Perovskite oxide
Oxygen octahedral rotation(OOR)
Half-order peak
Synchrotron radiation
Three-dimensional diffraction
作者简介
第一作者:陶亚军,女,1996年出生,2017年毕业于安徽大学,现为博士研究生,研究领域为外延薄膜的同步辐射三维衍射数据的模拟分析;通信作者:罗震林,E-mail:zlluo@ustc.edu.cn。
