Lattice Dynamics and Phase Transitions in Nanoscale Ferroelectric Heterostructures

纳米级铁电异质结构中的晶格动力学和相变

• 批准号: 0705127
• 负责人: Dmitri Tenne
• 金额: $ 24万
• 依托单位: Boise State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-01 至 2011-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0705127&HistoricalAwards=false
• 关键词: Lattice; Dynamics; Phase; Transitions; Nanoscale

Non-technical abstract:Modern science and technology of electronic materials have moved rapidly towards artificially engineered structures at nanometer (one billionth of a meter) scales. Physical behavior of materials at nanoscale is principally different from that of macroscopic materials in many aspects. The objective of this project is experimental investigation of fundamental physical properties of nanoscale ferroelectrics - 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. Shrinking dimensions down to nanometer scale demand characterization techniques capable of probing the fundamental properties of ferroelectric nanostructures. This project will utilize optical spectroscopic techniques using ultraviolet light to probe the atomic vibrations in nanoscale ferroelectric materials, which are essential for understanding their practically important properties. The experimental results to be obtained will test the validity of current theories of ferroelectrics and will contribute to a comprehensive understanding of nanoscale ferroelectricity. The proposed research will be closely integrated into the educational program at Boise State University, actively involving undergraduate and graduate students in the cutting-edge research and training, and acting as a catalyst for the effective use of the state-of-the-art optical instrumentation for educational purposes. The project will enhance Boise State's strength in the field of condensed-matter physics and materials science, which aligns perfectly with Boise State's strategic goal of becoming a metropolitan research university.Technical abstract:Ferroelectrics are a class of materials possessing a spontaneous electric polarization, which can be switched by the application of an electric field. Ferroelectrics exhibit a wide variety of interesting properties making them extremely attractive for applications in various electronic and optoelectronic devices. In recent years, the science and technology of ferroelectrics have moved rapidly towards artificially engineered thin films and multilayer structures at nanometer scales. A fundamental property of ferroelectrics is the dynamics of crystal-lattice vibrations, which is related to many of their practically important properties. This project focuses on the experimental study of lattice vibrations and phase transitions in nanoscale ferroelectrics by the novel technique of ultraviolet Raman spectroscopy. It will address several issues of major importance for understanding nanoscale ferroelectricity, such as the effects of strain and reducing size on ferroelectric behavior. The experimental results will test the validity of current theories of ferroelectrics, and will contribute to a comprehensive understanding of nanoscale ferroelectricity. 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 acting as a catalyst for the 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已迅速朝着人工设计的纳米（十亿米）尺度上的人工设计结构。纳米级材料的物理行为主要与许多方面的宏观材料不同。该项目的目的是对纳米级铁电的基本物理特性的实验研究 - 一类有趣且实际上重要的电子材料类别，具有高潜力用于在各种设备中的应用，例如计算机记忆或微波电子设备。缩小尺寸降低到纳米尺度的需求表征技术，能够探测铁电纳米结构的基本特性。该项目将使用紫外线利用光谱技术来探测纳米级铁电材料中的原子振动，这对于理解其实际重要特性至关重要。要获得的实验结果将测试铁电的当前理论的有效性，并将有助于对纳米级铁电性的全面理解。拟议的研究将紧密整合到博伊西州立大学的教育计划中，积极涉及本科生和研究生参与尖端的研究和培训，并作为有效使用先进光学的催化剂用于教育目的的仪器。该项目将增强博伊西州立大学在凝结物理和材料科学领域的实力，该物理和材料科学与博伊西州立大学成为大都市研究大学的战略目标完全一致。技术摘要：铁电摘要是具有自发性偏光的一类材料，该材料类别，该材料是一种材料，该材料是一种材料可以通过电场的应用切换。铁电器表现出各种有趣的特性，使其对在各种电子和光电设备中的应用都极具吸引力。近年来，铁电的科学和技术在纳米尺度上迅速朝着人工设计的薄膜和多层结构进行了迅速发展。铁电的基本特性是晶体栅极振动的动力学，这与它们的许多实际重要特性有关。该项目的重点是通过紫外拉曼光谱的新技术对纳米级铁电的晶格振动和相变的实验研究。它将解决一些对于理解纳米级铁电性的重要性问题，例如应变和减少大小对铁电行为的影响。实验结果将测试铁电特学当前理论的有效性，并有助于对纳米级铁电性的全面理解。拟议的研究将紧密整合到博伊西州立大学的教育计划中，积极参与研究和培训的本科生和研究生，并充当有效利用最先进的光学仪器的催化剂。