Raman Spectroscopy of Nanoscale Ferroelectric and Multiferroic Thin Films and Superlattices

纳米级铁电和多铁薄膜和超晶格的拉曼光谱

• 批准号: 1006136
• 负责人: Dmitri Tenne
• 金额: $ 28.5万
• 依托单位: Boise State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-01 至 2014-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1006136&HistoricalAwards=false
• 关键词: Raman; Spectroscopy; Nanoscale; Ferroelectric; Multiferroic

****NON-TECHNICAL ABSTRACT****Modern science and technology of electronic materials increasingly focuses on the development of novel, artificially engineered structures on the nanometer (one billionth of a meter) scale. The physical behavior of materials at the nanoscale is principally different from that of macroscopic materials in many aspects, opening new opportunities for the design of materials with superior properties for device applications. This project will experimentally investigate the fundamental physical properties of nanoscale ferroelectrics and multiferroics, an interesting and practically important class of electronic materials with high potential for applications in various devices, such as computer memories or microwave electronic devices. The project will utilize optical spectroscopic techniques to probe fundamental properties related to the atomic vibrations and structural transformations under a variety of conditions. The experimental results of the project will test the validity of current theories of ferroelectrics and multiferroics, thereby contributing to a comprehensive understanding of their properties. The proposed research will be closely integrated into the educational program at Boise State University, involving undergraduate and graduate students in research and training, promoting an active use of the state-of-the-art optical instrumentation for educational purposes, and supporting the development of new graduate programs. ****TECHNICAL ABSTRACT****Ferroelectrics are materials possessing a spontaneous electric polarization, which can be switched by the application of an electric field. Ferroelectrics and multiferroics, materials that exhibit both magnetic and ferroelectric ordering, are the focus of much active research with an abundance of basic science to be studied and novel applications to be explored. In recent years, science and technology of ferroelectrics and multiferroics have moved towards artificially engineered thin films and multilayer structures at nanometer scales. The dynamics of lattice vibrations is a fundamental property of ferroelectrics, related to many of their important physical properties, and Raman spectroscopy is one of the most powerful analytical techniques for studying the lattice vibrations. This project will utilize ultraviolet Raman spectroscopy to address several issues of major importance for understanding the behavior of nanoscale ferroelectrics and multiferroics, such as temperature-strain phase diagrams of thin films and heterostructures, the effect of an electric field on lattice dynamics and phase transitions, effects of off-stoichiometry on the properties of homo- and heteroepitaxial ferroelectric films, and ferroelectric and structural transformations in strained films of novel materials. The proposed research will be closely integrated into the educational program at Boise State University, actively involving undergraduate and graduate students in research and training and promoting the continued effective use of the state-of-the-art optical instrumentation for educational purposes.

****非技术摘要****电子材料的现代科学和技术越来越集中于纳米量表上新颖的，人工设计的结构（一十亿米）量表的发展。 纳米级材料在许多方面的物理行为主要与宏观材料的物理行为不同，这为设计具有卓越特性的材料设计了新的机会。 该项目将在实验中研究纳米级铁电和多表情的基本物理特性，这是一类有趣且实际上重要的电子材料类，具有在各种设备（例如计算机记忆或微波电子设备）中应用的高潜力。 该项目将利用光谱技术在各种条件下探测与原子振动和结构转换有关的基本特性。 该项目的实验结果将测试铁电和多表情当前理论的有效性，从而有助于对其性质的全面理解。 拟议的研究将紧密整合到博伊西州立大学的教育计划中，涉及本科生和研究生研究和培训，并积极利用最先进的光学仪器来进行教育目的，并支持发展新的研究生课程。 ****技术摘要****铁电源是具有自发性极化的材料，可以通过使用电场来切换。 磁性和铁电序表现出的材料是铁电极和多表情，是许多积极研究的重点，并需要研究大量的基础科学，并需要探索新颖的应用。 近年来，铁电和多表演技术的科学和技术已在纳米尺度上朝着人工设计的薄膜和多层结构转向。 晶格振动的动力学是铁电的基本特性，与它们的许多重要物理特性有关，拉曼光谱是研究晶格振动的最强大的分析技术之一。 该项目将利用紫外线拉曼光谱法来解决几个对于了解纳米级铁电和多表色的行为至关重要的问题，例如薄膜和异质结构的温度 - 晶体相图，这是电场对晶格动力学和相转换的影响，材料计量学对新型材料的紧张薄膜中同型和杂质铁电膜以及铁电和结构转化的特性的影响。 拟议的研究将紧密整合到博伊西州立大学的教育计划中，积极涉及本科生和研究生参与研究和培训，并促进持续有效利用最先进的光学仪器出于教育目的。