Pushing the Boundaries of Kinetic Stability in Metastable Perovskite Oxides

突破亚稳态钙钛矿氧化物动力学稳定性的界限

• 批准号: 2004455
• 负责人: Paul Maggard
• 金额: $ 50万
• 依托单位: North Carolina State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-06-01 至 2024-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2004455&HistoricalAwards=false
• 关键词: Pushing; Boundaries; Kinetic; Stability; Metastable

Part 1. Non-Technical Summary One of the major limitations in the discovery and design of new materials is the capability of predicting which compounds can potentially be synthesized. The underlying fundamental principles are not well understood and have historically required extensive trial and error. This project, supported by the Solid State and Materials Chemistry program within the Division of Materials Research, investigates and pushes the boundaries of synthesizability of crystalline solids, enabling the development of new strategies for preparing future technological materials. Discoveries stemming from the research efforts can provide new methods to prepare, for example, less toxic or more energy-efficient compounds that are critically important to the nation’s semiconductor and electronic ceramics industries. More generally, the advancement of strategies to synthesize materials over a wider attainable range of compositions and structures enables the rapid acceleration of their technological development. An in-depth characterization of the local and long-range structural features is aimed at understanding the impacts on the local structure and/or disorder of materials that occur at the edges of synthesizability. The inspiration and training of the next generation of scientists is facilitated within these technologically relevant basic research activities, including professional experiences at national laboratories and the development of research experiences for high school and community college teachers. The educational activities also emphasize the recruitment and participation of research students from underrepresented groups in STEM disciplines. Part 2. Technical SummaryMetastable crystalline solids are ubiquitous and can be commonly found as a result of either synthetic or naturally occurring processes, such as in the formation of crystalline diamond or in the synthesis of austenite stainless steel. The synthesis of metastable solids with technologically relevant properties, but that are extremely difficult or impossible to prepare, is a growing limitation in many research fields. The central objective of the research project is to elucidate and exploit the underlying factors that can govern the kinetic stabilization of metastable phases. Research thrusts specifically focus on metastable Sn(II)-containing perovskites that have potential applications as new lead-free ferroelectrics and as small bandgap semiconductors. The synthetic component is directed toward the discovery of new pathways to increase the range of synthesizability that can be experimentally achieved with the use of reaction conditions that can, for example, drive product formation while controlling ion diffusion and phase segregation in order to inhibit decomposition. Structural characterization by X-ray and neutron scattering techniques is aimed at answering key questions regarding the formation and decomposition pathways of these compounds. The extent and distribution of local and long-range structural disorder is probed at the precipices of energetically downhill decomposition pathways and the resulting new insights can help to push the limits of kinetic stabilization. Experimental efforts are complemented with quantification of thermodynamic relationships using open materials databases and density functional theory. Educational initiatives within this project, which is supported by the Solid State and Materials Chemistry program in the Division of Materials Research, include research training of undergraduate and graduate students, involvement of high school and community college teachers in research, and offering of an annual workshop on Rietveld methods for learners at a range of stages in their education.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

部分1. 发现和设计新材料的主要限制之一是预测哪些化合物可能被合成的能力。 基本的基本原则没有得到很好的理解，历史上需要广泛的试验和错误。 该项目由材料研究部内的固态和材料化学计划支持，研究并推动结晶固体的可合成性的界限，从而为制备未来的技术材料制定新的战略。 研究工作的发现可以提供新的方法来制备毒性更低或更节能的化合物，这些化合物对国家的半导体和电子陶瓷行业至关重要。 更一般地说，在更广泛的可实现的组成和结构范围内合成材料的策略的进步使得它们的技术发展能够迅速加速。 对局部和长程结构特征的深入表征旨在了解对局部结构的影响和/或发生在可合成性边缘的材料的无序。 在这些与技术有关的基础研究活动中促进了下一代科学家的启发和培训，包括在国家实验室的专业经验以及为高中和社区学院教师发展研究经验。 教育活动还强调从STEM学科代表性不足的群体中招募和参与研究生。 部分2.技术概述亚稳晶体固体是普遍存在的，并且通常可以作为合成或天然存在的过程的结果而发现，例如在结晶金刚石的形成中或在奥氏体不锈钢的合成中。 合成具有技术相关性质但极难或不可能制备的亚稳固体在许多研究领域中是一个日益增长的限制。 该研究项目的中心目标是阐明和利用潜在的因素，可以支配的亚稳相的动力学稳定。 研究重点特别集中在亚稳态含Sn（II）的钙钛矿，这些钙钛矿具有作为新型无铅铁电体和小带隙半导体的潜在应用。 该合成组分旨在发现新的途径以增加可合成性的范围，该可合成性可以通过使用反应条件在实验上实现，该反应条件可以例如驱动产物形成，同时控制离子扩散和相分离以抑制分解。 X射线和中子散射技术的结构表征旨在回答有关这些化合物的形成和分解途径的关键问题。 的程度和分布的本地和远程结构紊乱的能量下坡分解途径的悬崖，由此产生的新的见解可以帮助推动动力学稳定的极限进行了探讨。 实验工作的补充与量化的热力学关系，使用开放的材料数据库和密度泛函理论。 该项目中的教育举措得到材料研究部门固态和材料化学项目的支持，包括本科生和研究生的研究培训、高中和社区大学教师参与研究，并为处于不同教育阶段的学习者提供Rietveld方法的年度研讨会。该奖项反映了NSF的法定使命，通过使用基金会的知识价值和更广泛的影响审查标准进行评估，认为值得支持。

项目成果

Pushing the Limits of Metastability in Semiconducting Perovskite Oxides for Visible-Light-Driven Water Oxidation

• DOI: 10.1021/acs.chemmater.0c00044
• 发表时间: 2020-04-14
• 期刊: CHEMISTRY OF MATERIALS
• 影响因子: 8.6
• 作者: O'Donnell, Shaun;Chung, Ching-Chang;Maggard, Paul A.
• 通讯作者: Maggard, Paul A.

Solid State Aspects of Energy Conversion

能量转换的固态方面

• 发表时间: 2021
• 期刊: The Electrochemical Society interface
• 作者: Maggard, Paul A.

Structure, Stability, and Photocatalytic Activity of a Layered Perovskite Niobate after Flux-Mediated Sn(II) Exchange

• DOI: 10.1021/acs.inorgchem.1c03846
• 发表时间: 2022-03-07
• 期刊: INORGANIC CHEMISTRY
• 影响因子: 4.6
• 作者: O'Donnell, Shaun;Smith, Avery;Maggard, Paul A.
• 通讯作者: Maggard, Paul A.

In Search of the “Perfect” Inorganic Semiconductor/Liquid Interface for Solar Water Splitting

寻找用于太阳能水分解的“完美”无机半导体/液体界面

• DOI: 10.1149/2.f07211if
• 发表时间: 2021
• 期刊: The Electrochemical Society Interface
• 作者: Rajeshwar, Krishnan;Maggard, Paul A.;O’Donnell, Shaun
• 通讯作者: O’Donnell, Shaun

Switching Lead for Tin in PbHfO 3 : Noncubic Structure of SnHfO 3 **

PbHfO 3 中锡的开关引线：SnHfO 3 的非立方结构 **

• DOI: 10.1002/anie.202312130
• 发表时间: 2023
• 期刊: Angewandte Chemie International Edition
• 作者: Gabilondo, Eric A.;Newell, Ryan J.;Broughton, Rachel;Koldemir, Aylin;Pöttgen, Rainer;Jones, Jacob L.;Maggard, Paul A.
• 通讯作者: Maggard, Paul A.