Magnetic Field-Assisted Processing of Piezoelectric/Magnetostrictive Thin Film Composites to Enhance Properties

这项资助的研究目标在于阐明通过磁场辅助加工获得的薄膜多相多层的晶体织构增强的基本机制。这项研究将回答确定磁场辅助加工是否可以对磁致伸缩/压电（MS/PE）薄膜复合材料（tfc）产生变革性影响的基本问题。为此，将研究许多磁致伸缩和压电材料，包括软硬PZT组合物，PMN-xPT组合物，各种掺杂和未掺杂的镍和钴铁氧体，以及Terfenol-D。需要解决的具体问题包括控制与层厚度无关的压电和磁致伸缩材料的微观结构，微观结构控制对各种层界面行为的影响，以及压电和磁致伸缩层织构与层间性能耦合之间的关系。这些是决定磁场处理是否可以成为制造用于多铁性应用的高性能多层tfc的关键因素的关键问题。这项拨款的结果将在发展磁致伸缩/压电tfc的磁场处理的基础科学基础与生产高质量多层薄膜的制造相关技术的技术影响之间的差距方面发挥重要作用。然后，这些薄膜可以根据成分、层厚度、层数等进行设计，以适应高灵敏度、便携式、磁场传感器和地面能量采集器等应用。具有外延状微结构和性能的多层薄膜的出现将为多铁系统的发展提供一个重要的新方向。教育和推广活动将分为三个模块：研究生教育和指导，包括开发新的研究生课程“铁材料：结构、性能、制造和应用”，本科生的研究经验，以及为女性和少数民族工程专业学生提供的K-12推广活动。

The research objectives of this grant lie in elucidating the fundamental mechanisms that enhance crystallographic texturing of thin film, multi-phase multilayers obtained by magnetic field-assisted processing. This research will answer the essential questions that determine if magnetic field assisted processing can have a transformative effect on magnetostrictive/piezoelectric (MS/PE) thin film composites (TFCs). Towards this end, a number of magnetostrictive and piezoelectric materials will be studied, including soft and hard PZT compositions, PMN-xPT compositions, a wide range of doped and undoped nickel and cobalt ferrites, and Terfenol-D. Specific issues to be addressed include controlling the microstructure of piezoelectric and magnetostrictive materials independent of layer thicknesses, impact of microstructural control on the behavior of the various layer interfaces, and the relationships between piezoelectric and magnetostrictive layer texture and the interlayer property coupling. These are the key questions that determine if magnetic field processing can become a key element for manufacturing high performance multilayer TFCs for multiferroic applications.The results of this grant will play an important role in bridging the gap between developing the underlying science basis for magnetic field processing of magnetostrictive/piezoelectric TFCs with the technological impact of a manufacturing-relevant technique for producing high quality multilayer films. These films can then be engineered for compositions, layer thickness, number of layers, etc., to suit applications such as high sensitivity, portable, magnetic field sensors and terrestrial energy harvesters. The availability of multilayer films with epitaxial-like microstructures and properties will provide an important new direction for the development of multiferroic systems. The educational and outreach activities will be executed in three modules: graduate student education and mentoring, including the development of a new graduate course on Ferroic Materials: Structure, Properties, Manufacturing and Applications, research experience for undergraduate students, and K-12 outreach activities for female and minority engineering students.