Collaborative Research: U.S.-Ireland R&D Partnership Antiferroelectricity, Ferrielectricity and Ferroelectricity in the Archetypal Antiferroelectric PbZrO3 at Small Scale

非技术性研究在NSF材料研究部陶瓷计划的支持下，这项由两个美国机构和两个欧洲同行在北爱尔兰和爱尔兰共和国开展的合作努力，试图更好地了解从毫米和百分米到纳米长度尺度的材料功能。具体地说，该项目将解决氧化物中电偶极子的纳米级组织，这些组织可能共同导致较大长度尺度上可切换极化的存在或不存在。如果研究成功，这项研究将使下一代微纳级高力和高位移执行器和换能器、超高储能设备、小型化电压调节器、固态冷却、光电和电子设备成为可能。示例应用领域包括医疗保健(包括微手术)、制造、农业、灾难管理、健康和救援行动中的下一代远程控制机器人设备，以及紧凑型轻型航空航天应用。此外，团队成员的密切合作，包括工艺、先进的表征方法和材料理论的专业知识，将为参与研究的学生带来无与伦比的全面学习体验。在这个项目中对学生和年轻研究人员的培训将产生熟练的人力资本，适合于继续进行先进的研究或在相关行业产生有价值的影响。技术总结这项工作的总体目标是通过多管齐下的纳米极化理论和实验研究，在NSF材料研究部陶瓷计划的支持下，促进对PbZrO_3薄膜和纳米结构中反铁电的基本理解。具体地说，这项工作将把微观结构变化和宏观性质联系起来，探索PbZrO_3薄膜和纳米结构中经典的反铁电(AFE)、铁电(FIE)和铁电(FE)行为的稳定性：(1)分布的残余应力/应变分布的厚度减少；(2)尺寸限制导致一定范围的表面积/体积比和减少的横向约束；(3)薄膜的晶体取向，材料的大的固有各向异性可能导致不同的稳定标准，从而导致不同的临界参数(外加电场、温度、尺寸)在AFE、FIE和FE行为之间的转变。同时，理论工作将从纳米尺度评估材料在增大尺寸时的行为，为(S)从纳米尺度稳定的铁电相到(中间)铁电相，到宏观尺度和整体稳定的原型反铁电相的转变提供见解。在该计划期间对学生和年轻研究人员的培训将产生熟练的人力资本，适合继续先进的研究或在相关行业产生有价值的影响。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

NON-TECHNICAL SUMMARYWith support from the Ceramics Program in NSF’s Division of Materials Research, this collaborative effort, between two US-based institutions and two European counterparts in Northern Ireland and the Republic of Ireland, attempts to better understand material functionalities from milli- and centi-meter to nano-meter length scales. Specifically, this project will address the nanoscale organization of electrical dipoles in oxides that can collectively lead to presence or absence of switchable polarization at larger length scales. When successful, this research will enable the next-generation micro- and nano-scale high-force and high-displacement actuators and transducers, ultrahigh energy storage devices, miniaturized voltage regulators, solid-state cooling, electro-optic and electronic devices. Example application areas include next-generation remote-controlled robotic devices in healthcare (including micro-surgery), manufacturing, agriculture, disaster management, health and rescue operations, and compact lightweight aerospace applications. Additionally, the close collaboration of team members, with expertise spanning processing, advanced characterization methods and materials theory, will result in an unsurpassed and rounded learning experience for the students involved in this research. The training of the students and young researchers during this program will result in skilled human capital, suited to either continue advanced research or make a valuable impact in related industries.TECHNICAL SUMMARYThe overarching goal of this work, supported by the Ceramics Program in NSF’s Division of Materials Research, is to advance the fundamental understanding of antiferroelectricity in PbZrO3 thin films and nanostructures, through multipronged theoretical and experimental studies of nanoscale polarization. Specifically, this work will correlate microscopic structural changes with macroscopic properties in this archetypal antiferroelectric, exploring the stability of classical antiferroelectric (AFE), ferrielectric (FiE), and ferroelectric (FE) behavior in PbZrO3 thin films and nanostructures as a function of: (1) thickness reduction with distributed residual stress/strain profiles; (2) size confinement resulting in a range of surface-to-volume ratios with reduced lateral constraint; and (3) crystallographic orientation of the films, where a large inherent anisotropy in the material might result in different stabilization criteria and hence, different critical parameters (external electric fields, temperature, size) for transitions between AFE, FiE and FE behaviors. In parallel, theoretical efforts will evaluate material behavior at increasing size from the nanoscale, offering insights into transition(s) from the nanoscale-stable ferroelectric phase, to an (intermediate) ferrielectric phase, to the macroscale and bulk-stable and archetypal antiferroelectric one. The training of the students and young researchers during this program will result in skilled human capital, suited to either continue advanced research or make a valuable impact in related industries.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.