Local cation ordering in compositionally complex Ruddlesden–Popper n = 1 oxides
Local cation ordering in compositionally complex Ruddlesden–Popper n = 1 oxides
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DOI：
10.1063/5.0144766
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发表时间：
2023-05
期刊：
影响因子：
6.1
通讯作者：
Bo Jiang;K. Pitike;D. Lin;Stephen C. Purdy;Xin Wang;Yafan Zhao;Yuanpeng Zhang;Peter C. Metz-
中科院分区：
文献类型：
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作者：
Bo Jiang;K. Pitike;D. Lin;Stephen C. Purdy;Xin Wang;Yafan Zhao;Yuanpeng Zhang;Peter C. Metz-
Ruddlesden-Popper（RP）层状钙钛矿结构由于其固有的可调谐性而引起人们极大的兴趣，并且组成复合氧化物（CCO）概念的出现和发展赋予RP家族更多的可能性。在此，在通过各种处理条件获得的镧缺乏的Lan+1BnO 3 n +1（n = 1，B = Mg、Co、Ni、Cu、Zn）的前两个报道的实施例中进行热力学稳定性、局部有序/无序和晶格畸变的综合评估。通过中子对分布函数分析揭示了RP-CCO中B位的化学短程有序（CSRO）和可控的过量间隙氧（δ）。反向蒙特卡罗分析的数据，大都会蒙特卡罗模拟，和扩展的X射线吸收精细结构分析意味着适度的磁性元素偏析的局部规模。此外，从头算分子动力学模拟结果从特殊的准随机结构不同意实验观察到的CSRO，但确认Jahn-Teller扭曲的CuO 6八面体。这些研究结果突出了控制局部有序/无序和过量间隙氧的层状RP-CCO的潜在机会，并表现出高度的自由度定制应用特定的性能。他们还建议需要扩展理论和数据建模方法，以应对CCO和相关高熵阶段的固有挑战。
The Ruddlesden–Popper (RP) layered perovskite structure is of great interest due to its inherent tunability, and the emergence and growth of the compositionally complex oxide (CCO) concept endows the RP family with further possibilities. Here, a comprehensive assessment of thermodynamic stabilization, local order/disorder, and lattice distortion was performed in the first two reported examples of lanthanum-deficient Lan+1BnO3n+1 (n = 1, B = Mg, Co, Ni, Cu, Zn) obtained via various processing conditions. Chemical short-range order (CSRO) at the B-site and the controllable excess interstitial oxygen (δ) in RP-CCOs are uncovered by neutron pair distribution function analysis. Reverse Monte Carlo analysis of the data, Metropolis Monte Carlo simulations, and extended x-ray absorption fine structure analysis implies a modest degree of magnetic element segregation on the local scale. Further, ab initio molecular dynamics simulations results obtained from special quasirandom structure disagree with experimentally observed CSRO but confirm Jahn–Teller distortion of CuO6 octahedra. These findings highlight potential opportunities to control local order/disorder and excess interstitial oxygen in layered RP-CCOs and demonstrate a high degree of freedom for tailoring application-specific properties. They also suggest a need for expansion of theoretical and data modeling approaches in order to meet the innate challenges of CCO and related high-entropy phases.