Phase-field Models of Piezoelectric and Multiferroic Responses of Ferroelectric and Multiferroic Nanostructures

铁电和多铁纳米结构的压电和多铁响应的相场模型

• 批准号: 1006541
• 负责人: Long-Qing Chen
• 金额: $ 40万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-10-01 至 2015-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1006541&HistoricalAwards=false
• 关键词: Phase; field; Models; Piezoelectric; Multiferroic

TECHNICAL SUMMARYThis award supports theoretical and computational research on electro-magneto-mechanical couplings in ferroelectric and multiferroic nanostructures. Ferroelectrics and multiferroics are multi-functional materials that have many applications in devices such as actuators, sensors, and memory storage. The main objective of the project is to fundamentally understand the roles of mechanical and electrical boundary conditions in their ferroic responses. The focus is on the piezoelectric responses of nanoferroelectrics and the magnetoelectric coupling of self-assembled epitaxial nanocomposites of ferroelectric and ferromagnetic crystals. The phase-field approach will be employed in combination with mesoscale elasticity, electrostatic theory, and micromagnetics. The particular goals of the project are as follows:(1) The PI will develop and implement efficient numerical algorithms based on the spectral method for solving the phase-field, mechanical, electrostatic, and magnetostatic equations while taking into the appropriate electric and mechanical boundary conditions.(2) The PI will investigate the dependence of piezoelectric responses of ferroelectric nanostructures on substrate constraints as well as on the inhomogeneous stress distributions within a nanostructure due to presence of defects such as dislocations.(3) The PI will study the correlation between the multiferroic nanocomposite microstructure and the magnitude of magnetoelectric coupling effect. This research program involves active collaborations with applied mathematicians on the implementation of advanced numerical algorithms and with experimentalists on experimental validation of computational predictions and findings. The research under this award is expected to (i) significantly contribute to the fundamental understanding of the piezoelectric responses of nanoferroelectrics and magnetoelectric coupling effect of multiferroic nanocomposites, (ii) yield new phase-field formulations for modeling multiferroic domain structures, and (iii) produce advanced numerical algorithms for solving phase-field equations involving non-periodic boundary conditions. This award supports training graduate as well as undergraduate students through thesis and summer research. Software tools developed from the project will be incorporated into two graduate courses and an undergraduate course. The research findings will be disseminated to a wide audience through archival publications and conferences, review and overview papers, and active participation and lectures at interdisciplinary workshops. NON-TECHNICAL SUMMARYThis award supports theoretical and computational research on the properties and functionalities of ferroelectric and multiferroic oxides. Ferroelectrics and multiferroics are multi-functional materials that can produce two or more different types of responses when they are subjected to an external field. They have many potential applications in devices such as actuators, sensors, and computer memory storage. For example, a ferroelectric crystal can change both its shape and electric polarization when it is subject to an external mechanical stress. Electric polarization results when the negative electronic charge distribution is shifted from the positive charge distribution of the atomic nuclei in a crystal. In a multiferroic material, the magnitude and direction of both the magnetization and electric polarization can be altered by externally applying either an electric or a magnetic field. The research program has two main thrusts: The PI will investigate the so-called "piezoelectric response", which is related to the magnitude of the change in electric polarization under a mechanical stress or the degree of crystal shape deformation under an electric field. These effects will be examined in bulk ferroelectrics as well as in tiny structures of sizes that are approximately one billionth the size of the human hair. Secondly, the PI will investigate the so-called "magnetoelectric" coupling, which is related to the change in electric polarization under an applied magnetic field or the change in magnetization under an applied electric field. The PI will develop and apply various computational tools in these investigations. The overall goal is to optimize the multi-functionalities of such materials through computer simulations. The research program involves active collaborations with applied mathematicians on the implementation of advanced numerical algorithms and with experimentalists on experimental validation of computational predictions and findings.The project will contribute to human resource development by training graduate as well as undergraduate students through thesis and summer research. Software tools developed from the project will be incorporated into two graduate courses and an undergraduate course. The research findings will be disseminated to a wide audience through archival publications and conferences, review and overview papers, and active participation and lectures at interdisciplinary workshops.

技术摘要这一奖项支持铁电和多型纳米结构中电力机械耦合的理论和计算研究。 铁电和多效应是多功能材料，在执行器，传感器和内存存储等设备中具有许多应用。 该项目的主要目的是从根本上了解机械和电边界条件在其铁反反应中的作用。 重点是纳米曲线电离的压电响应以及铁电和铁磁晶体的自组装的同际纳米复合材料的磁电耦合。 相位场方法将与中尺度弹性，静电理论和微磁学结合使用。 该项目的特定目标如下：（1）PI将基于频谱方法来开发和实施有效的数值算法，以求解相位场，机械，机械，静电和磁静态方程，同时采用适当的电气和机械边界条件。由于存在缺陷，例如位错等缺陷，纳米结构内的不均应力分布。（3）PI将研究多效性纳米复合微结构与磁电耦合效应的大小之间的相关性。 该研究计划涉及与应用数学家在实施高级数值算法以及实验者实验验证计算预测和发现方面的积极合作。 该奖项下的研究有望（i）显着有助于对纳米表征的压电响应的基本理解，以及多表面纳米复合材料的磁电极和磁电耦合效应，（ii）产生新的相位公式，以产生建模阶段的新相位公式，并产生（III）的高级数量，并产生高级数量的型号，并产生高级数量的型号。非周期边界条件。 该奖项通过论文和夏季研究支持培训毕业生以及本科生。 该项目开发的软件工具将被纳入两个研究生课程和一门本科课程中。研究发现将通过档案出版物和会议，审查和概述论文以及在跨学科研讨会上的积极参与和讲座将广泛的受众传播给广泛的受众。非技术摘要这一奖项支持有关铁电和多种氧化物的性质和功能的理论和计算研究。 铁电和多效应是多功能材料，在经受外部野外的影响时可以产生两种或更多不同的响应。它们在执行器，传感器和计算机存储器存储等设备中具有许多潜在的应用。 例如，当铁电晶体受到外部机械应力时，它可以改变其形状和电化极化。 当负电子电荷分布从晶体中原子核的正电荷分布转移时，会产生电化极化。在多种材料中，磁化和电化极化的大小和方向可以通过外部施加电场或磁场来改变。 该研究计划有两个主要的推力：PI将研究所谓的“压电反应”，这与机械应力下电动极化的变化或电场下的晶体形状变形程度有关。这些效果将在散装铁电体以及尺寸的微小结构中进行检查，大约是人毛的大小十亿分之一。其次，PI将研究所谓的“磁电”耦合，该耦合与施加的磁场下的电极变化或在施加的电场下的磁化变化有关。 PI将在这些研究中开发并应用各种计算工具。总体目标是通过计算机模拟优化此类材料的多功能性。 该研究计划涉及与应用数学家的积极合作，以实施高级数值算法，并与实验者对计算预测和发现的实验验证。该项目将通过培训研究生以及通过论文和夏季研究来为人力资源发展做出贡献。 该项目开发的软件工具将被纳入两个研究生课程和一门本科课程中。研究发现将通过档案出版物和会议，审查和概述论文以及在跨学科研讨会上的积极参与和讲座将广泛的受众传播给广泛的受众。