Collaborative Research: Extrinsic Size Effects in Ferroelectric Thin Films

合作研究：铁电薄膜的外在尺寸效应

• 批准号: 1409399
• 负责人: Jacob Jones
• 金额: $ 43.88万
• 依托单位: North Carolina State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-15 至 2020-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1409399&HistoricalAwards=false
• 关键词: Collaborative; Research; Extrinsic; Size; Effects

NON-TECHNICAL DESCRIPTION: Ferroelectric materials are used to couple electrical and mechanical energy and store information. Therefore, they are used pervasively as sensors, actuators, and energy and memory storage components in microelectronics, ultrasonic devices, and consumer products. The properties of ferroelectric materials can change significantly as their size is reduced. In ferroelectric thin films, it is now widely recognized that significant size effects are observed at film thicknesses between 10 nm and 1 um. At these thicknesses, the effectiveness of these materials at storing and transducing energy is dramatically reduced - in some cases being suppressed to 20% of the values seen in their larger counterparts. Using state-of-the-art experimental approaches offered by a collaborative team of investigators, this project elucidates the atomistic origins of these size effects in ferroelectric thin films. This understanding enables the design and realization of next-generation devices at substantially smaller length scales with superior performance and functionality. Examples of devices impacted by this research include piezoelectric microelectromechanical systems and scaled capacitors.TECHNICAL DETAILS: The goal of the project is to develop a universal physical understanding of the fundamental structure-property-processing relationships that govern extrinsic size effects in ferroelectric thin films. The specific objectives include proving the extrinsic mechanism(s) affecting the size effects in ferroelectric thin films, quantifying the relative contributions from intrinsic and extrinsic mechanisms to properties, and establishing new fundamental structure-property-processing relationships. To accomplish these objectives, the Trolier-McKinstry group at Penn State synthesizes high-quality thin films and analyzes property measurements using Rayleigh and Preisach models. The Jones group at North Carolina State University uses in situ X-ray diffraction while applying voltage to quantify the intrinsic and extrinsic contributions under equivalent electrical loading conditions. The integrated results provide a quantitative understanding of contributions of intrinsic and extrinsic effects to the dielectric and piezoelectric coefficients in ferroelectric thin films as a function of film thickness and other key variables. The fundamental nature of the mechanisms and the results in the present work will be applicable to many ferroelectric thin film compositions including those being developed for high-temperature and lead(Pb)-free applications. Graduate students gain additional exposure to facilities and scientists through conducting experiments at the Advanced Photon Source at Argonne National Laboratory. The educational outreach program includes participation by the project participants at workshops and camps directed at elementary, middle school, and high school students. Students from underrepresented groups will be engaged in the project through targeted recruitment and outreach activities.

非技术描述：铁电材料用于耦合电能和机械能并存储信息。因此，它们广泛用作微电子、超声波设备和消费产品中的传感器、致动器以及能量和存储器存储组件。铁电材料的性质可以随着其尺寸的减小而显著改变。在铁电薄膜中，现在广泛认识到，在10 nm和1 μ m之间的膜厚度处观察到显著的尺寸效应。在这些厚度下，这些材料在储存和转换能量方面的有效性大大降低-在某些情况下被抑制到其较大对应物中所见值的20%。使用国家的最先进的实验方法提供了一个合作小组的研究人员，该项目阐明了这些尺寸效应的铁电薄膜的原子起源。这种理解使得能够设计和实现具有上级性能和功能的下一代器件，其长度尺度显著更小。受此研究影响的设备的例子包括压电微机电系统和缩放capacitors.Technical problems：该项目的目标是发展一个普遍的物理理解的基本结构，性能处理的关系，管理外在的铁电薄膜的尺寸效应。具体目标包括证明影响铁电薄膜尺寸效应的非本征机制，量化本征机制和非本征机制对性能的相对贡献，并建立新的基本结构-性能-工艺关系。为了实现这些目标，宾夕法尼亚州立大学的Trolier-McKinstry小组合成了高质量的薄膜，并使用Rayleigh和Preisach模型分析了性能测量。北卡罗来纳州州立大学的琼斯小组在施加电压的同时使用原位X射线衍射来量化等效电负载条件下的本征和非本征贡献。集成的结果提供了一个定量的理解的贡献的内在和外在的影响，在铁电薄膜的介电和压电系数作为膜厚度和其他关键变量的函数。在本工作中的机制和结果的基本性质将适用于许多铁电薄膜组合物，包括那些正在开发的高温和无铅（Pb）的应用。研究生通过在阿贡国家实验室的高级光子源进行实验，获得更多的设施和科学家。 教育推广计划包括项目参与者参加针对小学、初中和高中学生的讲习班和营地。将通过有针对性的征聘和外联活动，让代表性不足群体的学生参与该项目。