Achieving High Dielectric Constant Relaxor Ferroelectric Nanocrystals via a Hybridization-Induced Nanodomain Approach

通过杂交诱导纳米域方法实现高介电常数弛豫铁电纳米晶体

• 批准号: 1709420
• 负责人: Zhiqun Lin
• 金额: $ 45万
• 依托单位: Georgia Tech Research Corporation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-07-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1709420&HistoricalAwards=false
• 关键词: Achieving; Dielectric; Constant; Relaxor; Ferroelectric

Nontechnical Abstract:Nanostructured ferroelectric materials show great potential for future micro- and nano-electronic applications, including wearable medical sensors for human monitoring, non-volatile ferroelectric memory, piezoelectric/electrostrictive actuation, second harmonic generation imaging, energy harvesting and storage, electrocaloric cooling, and liquid crystal displays. Unfortunately, as the dimensions of ferroelectric materials decrease to a few tens of nanometers, their high dielectric property eventually disappears as a result of destabilization of the ferroelectric phase. Therefore, it is highly desirable to develop novel, high dielectric constant ferroelectric nanocrystals with stable ferroelectric phase and nanosized domains. The understanding of polymer defect-induced ferroelectric nanodomains within inorganic nanocrystals paves the way to create many other intriguing ferroelectric nanocrystals. Meanwhile, the research project is integrated with nanoscience education through close interactions among graduate students, undergraduate students, high school science teachers, and high school students in a multilevel learning experience inspired by the excitement of discovery at both Georgia Tech and Case Western Reserve University. The goals are to stimulate the interest of high school students in the area of science, technology, engineering, and mathematics (STEM), and better prepare undergraduate students for the STEM-related professions. To enhance the public awareness of nanoscience and nanotechnology, research findings are widely disseminated to multiple constituencies through publications in scientific journals, presentations at national conferences and workshops.Technical Abstract:This proposal aims to understand the effect of organic/inorganic hybridization on the nanoscopic ferroelectric phase and domain structures in polymer-tethered hybrid BaTiO3 nanocrystals, and extend the underlying mechanism to other lead-free relaxor ferroelectric systems to achieve high dielectric constants for various potential electrical applications. First, novel amphiphilic nonlinear block copolymers are rationally designed and synthesized. Subsequently, uniform polymer-tethered hybrid BaTiO3 nanocrystals with precisely tailored dimensions are crafted by employing amphiphilic nonlinear block copolymers as nanoreactors. The nanoscale ferroelectric phase and domain structures in polymer-tethered hybrid BaTiO3 nanocrystals are interrogated using high-resolution transmission electron microscopy, and the mechanism of their relaxor ferroelectric behavior can be unraveled. Finally, the underlying mechanism are extended to create other lead-free relaxor ferroelectric nanocrystals with even higher dielectric constants.

非技术摘要：纳米结构铁电材料显示出巨大的潜力，为未来的微和纳米电子应用，包括可穿戴医疗传感器的人体监测，非易失性铁电存储器，压电/电致伸缩致动，二次谐波产生成像，能量收集和存储，电热冷却，液晶显示器。不幸的是，当铁电材料的尺寸减小到几十纳米时，由于铁电相的不稳定，它们的高介电性质最终消失。因此，开发具有稳定铁电相和纳米畴的新型高介电常数铁电纳米晶是非常必要的。对无机纳米晶体中聚合物缺陷诱导的铁电纳米畴的理解为创造许多其他有趣的铁电纳米晶体铺平了道路。与此同时，该研究项目通过研究生，本科生，高中科学教师和高中学生之间的密切互动与纳米科学教育相结合，在格鲁吉亚理工学院和凯斯西储大学发现的兴奋的启发下，在多层次的学习体验。其目标是激发高中学生对科学，技术，工程和数学（STEM）领域的兴趣，并为本科生更好地准备STEM相关专业。为了提高公众对纳米科学和纳米技术的认识，研究成果通过科学期刊上的出版物、全国会议和研讨会上的演讲广泛传播给多个选区。技术摘要：该提案旨在了解有机/无机杂交对聚合物束缚的混合BaTiO 3纳米晶体中纳米级铁电相和畴结构的影响，并将其基本机制扩展到其他无铅驰豫铁电系统，以实现各种潜在电气应用的高介电常数。首先，合理设计合成了新型两亲性非线性嵌段共聚物。随后，均匀的聚合物拴系的混合钛酸钡纳米晶体与精确定制的尺寸制作通过采用两亲性非线性嵌段共聚物作为纳米反应器。利用高分辨透射电子显微镜研究了聚合物束缚的BaTiO 3纳米晶的纳米级铁电相和畴结构，揭示了其弛豫铁电行为的机理。最后，潜在的机制扩展到创建其他无铅弛豫铁电纳米晶体具有更高的介电常数。

项目成果

Synthesis of Amphiphilic and Double Hydrophilic Star-like Block Copolymers and the Dual pH-Responsiveness of Unimolecular Micelle

两亲双亲水星状嵌段共聚物的合成及单分子胶束的双pH响应性

• DOI: 10.1021/acs.macromol.0c00918
• 发表时间: 2020
• 期刊: Macromolecules
• 影响因子: 5.5
• 作者: Harn, Yeu-Wei;He, Yanjie;Wang, Zewei;Chen, Yihuang;Liang, Shuang;Li, Zili;Li, Qiong;Zhu, Lei;Lin, Zhiqun
• 通讯作者: Lin, Zhiqun

Understanding the Mechanism of Star-Block Copolymers as Nanoreactors for Synthesis of Well-Defined Silver Nanoparticles

了解星块共聚物作为纳米反应器合成明确银纳米粒子的机制

• 发表时间: 2018
• 期刊: Journal of emerging investigators
• 作者: Zhu, Albert;Li, Qiong;Chen, Xiaoyi
• 通讯作者: Chen, Xiaoyi