Exploring the Interplay between Charge, Strain and Polarization in Ferroelectric Nanostructures

探索铁电纳米结构中电荷、应变和极化之间的相互作用

• 批准号: 2034738
• 负责人: Xiaoqing Pan
• 金额: $ 64万
• 依托单位: University of California-Irvine
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-03-01 至 2025-02-28
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2034738&HistoricalAwards=false
• 关键词: Exploring; Interplay; between; Charge; Strain

NON-TECHNICAL DESCRIPTION: Ferroelectric materials are characterized by a spontaneous electric polarization, which can be reoriented with an applied electric field. The ability to form and manipulate nanoscale regions of uniform polarization (domains) makes ferroelectrics a promising candidate for future low-power electronic devices, particularly computer memories. When ferroelectrics is integrated with other materials, new and unique properties can emerge from interfaces where the two materials join. To understand these emergent properties, it is critical to characterize the atomic structure, chemical bonding, electric field, charge distribution at interfaces. Modern electron microscopy is capable of directly imaging the atomic structure, but the other properties must generally be inferred from these images. This project aims to develop new imaging methods that enable to determine all of these properties simultaneously. This will give a full picture of how and why unique properties can emerge at the interface and will inform the design and fabrication of future electronic devices. Although the research focuses on ferroelectrics, the microscopy techniques developed during and scientific knowledge gained from this project are broadly applicable to many different types of materials. The research is integrated with education and outreach activities to attract diverse junior scientists, including women and underrepresented minority groups, and will help train future leaders to address critical societal challenges.TECHNICAL DETAILS: This project leverages unique electron microscopy facilities at the Irvine Materials Research Institute where the PI serves as the director. This project aims to develop a novel four-dimensional scanning transmission electron microscopy (4D STEM) method that enables the measurement of atomic scale structure, local electric field, charge density, valence states, and polarization configuration in nanostructures and interfaces under different boundary conditions with atomic resolution. 4D STEM will also be combined with electron energy-loss spectroscopy and scanning probe microscopy in a unique multimodal approach to probe the atomic scale structure and properties of interfaces and to gain a fundamental understanding of the interaction between ferroelectric polarization, bound charge, epitaxial strain, charge screening, and structure reconstruction in ferroelectric interfaces under different conditions or surrounding topological defects in doped ferroelectric thin films. The detailed characterization of ferroelectric interfaces is required to gain deep insights into the atomic mechanisms of emergent phenomena at interfaces and provide guidance for engineering ferroelectric nanostructures with novel functionalities. The integration of this research with the education and training of students allows the results from this project to be disseminated to the diverse student populations on campus through coursework and independent studies for undergraduate students, as well as to high school students from diverse backgrounds through summer school programs, which promotes their interest in scientific research and 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.

非技术描述：铁电材料的特点是自发电极化，可以通过施加电场重新取向。形成和操纵均匀极化纳米级区域（域）的能力使铁电体成为未来低功耗电子设备（特别是计算机存储器）的有希望的候选者。当铁电体与其他材料集成时，两种材料连接的界面就会出现新的、独特的性能。为了理解这些新出现的特性，表征原子结构、化学键、电场、界面电荷分布至关重要。现代电子显微镜能够直接对原子结构进行成像，但其他性质通常必须从这些图像中推断出来。该项目旨在开发新的成像方法，能够同时确定所有这些特性。这将全面了解界面上如何以及为何会出现独特的属性，并将为未来电子设备的设计和制造提供信息。尽管该研究的重点是铁电体，但该项目期间开发的显微技术和从该项目中获得的科学知识广泛适用于许多不同类型的材料。该研究与教育和外展活动相结合，以吸引不同的初级科学家，包括女性和代表性不足的少数群体，并将帮助培训未来的领导者以应对关键的社会挑战。技术细节：该项目利用尔湾材料研究所独特的电子显微镜设施PI 担任董事。该项目旨在开发一种新颖的四维扫描透射电子显微镜（4D STEM）方法，能够测量不同边界条件下纳米结构和界面的原子尺度结构、局部电场、电荷密度、价态和极化配置原子分辨率。 4D STEM 还将以独特的多模式方法与电子能量损失光谱和扫描探针显微镜相结合，探测原子尺度结构和界面特性，并获得对铁电极化、束缚电荷、外延应变、不同条件下或掺杂铁电薄膜中拓扑缺陷周围铁电界面的电荷筛选和结构重建。需要对铁电界面进行详细表征，以深入了解界面处出现现象的原子机制，并为设计具有新颖功能的铁电纳米结构提供指导。这项研究与学生的教育和培训相结合，使该项目的成果能够通过本科生的课程作业和独立研究传播给校园内的不同学生群体，并通过暑期学校传播给来自不同背景的高中生该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Stability-limiting heterointerfaces of perovskite photovoltaics

钙钛矿光伏电池的稳定性限制异质界面

• DOI: 10.1038/s41586-022-04604-5
• 发表时间: 2022-03-15
• 期刊: Nature
• 影响因子: 64.8
• 作者: Shaun Tan;Tianyi Huang;I. Yavuz;Rui Wang;Taegeun Yoon;Mingjie Xu;Qiyu Xing;Keonwoo Park;Do‐Kyoung Lee;Chung;Ran Zheng;Taegeun Yoon;Yepin Zhao;Hao;Dong Meng;Jingjing Xue;Y. Song;X. Pan;N. Park;Jin‐Wook Lee;Yang Yang
• 通讯作者: Yang Yang

Nanoscale imaging of phonon dynamics by electron microscopy

电子显微镜声子动力学纳米级成像

• DOI: 10.1038/s41586-022-04736-8
• 发表时间: 2021-05-25
• 期刊: Nature
• 影响因子: 64.8
• 作者: Chaitanya A. Gadre;Xingxu Yan;Qichen Song;Jie Li;Lei Gu;H. Huyan;T. Aoki;Sheng;Gang Chen;R. Wu;Xiaoqing Pan
• 通讯作者: Xiaoqing Pan

Direct observation of polarization-induced two-dimensional electron/hole gases at ferroelectric-insulator interface

直接观察铁电体-绝缘体界面处极化诱导的二维电子/空穴气体

• DOI: 10.1038/s41535-021-00389-4
• 发表时间: 2021-10
• 期刊: npj Quantum Materials
• 影响因子: 5.7
• 作者: Huyan, Huaixun;Addiego, Christopher;Yan, Xingxu;Gadre, Chaitanya A.;Melville, Alexander;Schlom, Darrell G.;Pan, Xiaoqing
• 通讯作者: Pan, Xiaoqing

Direct observation of elemental fluctuation and oxygen octahedral distortion-dependent charge distribution in high entropy oxides

直接观察高熵氧化物中的元素涨落和氧八面体畸变相关的电荷分布

• DOI: 10.1038/s41467-022-30018-y
• 发表时间: 2022-04-29
• 期刊: Nature Communications
• 影响因子: 16.6
• 作者: L. Su;H. Huyan;Abhishek Sarkar;Wenpei Gao;Xingxu Yan;Christopher Addiego;R. Kruk;H. Hahn;Xiaoqing Pan
• 通讯作者: Xiaoqing Pan

In-plane quasi-single-domain BaTiO3 via interfacial symmetry engineering

通过界面对称工程制备面内准单畴 BaTiO3

• DOI: 10.1038/s41467-021-26660-7
• 发表时间: 2021-12
• 期刊: Nature Communications
• 影响因子: 16.6
• 作者: Lee, J. W.;Eom, K.;Paudel, T. R.;Wang, B.;Lu, H.;Huyan, H. X.;Lindemann, S.;Ryu, S.;Lee, H.;Kim, T. H.;et al
• 通讯作者: et al