Self-Assembled Polydomain Ferroelectric and Ferromagnetic Heterostructures

自组装多域铁电和铁磁异质结构

• 批准号: 0210512
• 负责人: Alexander Roytburd
• 金额: $ 34.54万
• 依托单位: University of Maryland, College Park
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-08-01 至 2005-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0210512&HistoricalAwards=false
• 关键词: Self; Assembled; Polydomain; Ferroelectric; Ferromagnetic

The project is a collaborative theoretical and experimental study of self-assembled oxide poly-domain architectures in film/substrate heterostructures. The polydomain structures of thin films on substrates are strongly determined by their mechanical constraints: the misfit between the film and substrate, the orientation and local structure of the film/substrate interface, and the geometri-cal configuration of the film. The goal of this research is to design controlled polydomain struc-tures through constraint engineering to obtain enhanced functional properties of ferroelectric and ferromagnetic film materials. Different techniques of constraint engineering (modification of film/substrate misfit, patterning of films and film/substrate interfaces) will be employed to achieve this goal. These techniques will be developed and tested on PbTiO3-Pb(Zn,Ti)O3 (PZT) tetragonal films, which demonstrate strong piezoeffects. Subsequently, the techniques will be ap-plied to films of highly adaptive ferroelectrics with compositions near the morphotropic phase boundary in the PZT system. Polydomain engineering will also be applied to ferromagnetic oxides of the La1-xSrxMnO3 system, which exhibit colossal magneto-resistance and promising mag-netostrictive properties. The research objectives are sought through a combination of theory, modeling and experimental verification of theoretically obtained domain design principles. Theo-retical work will include analysis of internal stresses and energetics of polydomain structures, phase field modeling for non-patterned films, and finite element analysis (FEM) for local stress effects and patterned films. The experimental work will consist of thin-film processing, engi-neering of patterned films, design of polydomain structures and their characterization by X-ray diffraction, electron microscopy, scanning force microscopy and magneto-optical imaging tech-nique. Measurement of electric, magnetic and mechanical properties of films will also be per-formed. %%% The project addresses fundamental research issues in areas of electronic materials science having technological relevance. An important feature of the project is the strong emphasis on education, and the integration of research and education. The combined resources, including experimental and theoretical methods, provide special opportunities for education and training of graduate stu-dents involved in highly interdisciplinary forefront research.***

该项目是一个合作的理论和实验研究的自组装氧化物多域架构的薄膜/衬底异质结构。基底上薄膜的多畴结构在很大程度上取决于薄膜与基底之间的失配、薄膜/基底界面的取向和局部结构以及薄膜的几何构型等力学约束。本研究的目标是通过约束工程设计可控的多畴结构，以获得铁电和铁磁薄膜材料的增强功能特性。将采用不同的约束工程技术（膜/基底失配的修改、膜和膜/基底界面的图案化）来实现这一目标。这些技术将被开发和测试的PbTiO 3-Pb（Zn，Ti）O3（PZT）tetraxide薄膜，表现出强大的压电效应。随后，该技术将被应用于PZT系统中的准同型相界附近的组分的高度自适应铁电体的薄膜。多畴工程也将被应用到La_（1-x）Sr_xMnO_3系统的铁磁氧化物，其表现出巨大的磁电阻和有前途的磁致伸缩性能。研究目标是通过理论，建模和实验验证理论上获得的域设计原则相结合。理论工作将包括多畴结构的内应力和能量分析、非图案化薄膜的相场建模以及局部应力效应和图案化薄膜的有限元分析。实验工作将包括薄膜加工、图形化薄膜的设计、多畴结构的设计以及用X射线衍射、电子显微镜、扫描力显微镜和磁光成像技术对其进行表征。薄膜的电、磁和机械性能的测量也将被执行。该项目解决了具有技术相关性的电子材料科学领域的基础研究问题。该项目的一个重要特点是高度重视教育，并将研究与教育相结合。综合资源，包括实验和理论方法，为参与高度跨学科前沿研究的研究生提供教育和培训的特殊机会。