Complex Perovskites: Chemical & Structural Complexity as a Route to New Functional Materials

复杂钙钛矿：化学

• 批准号: 0907356
• 负责人: Patrick Woodward
• 金额: $ 38.29万
• 依托单位: Ohio State University Research Foundation -DO NOT USE
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-06-01 至 2012-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0907356&HistoricalAwards=false
• 关键词: Complex; Perovskites; Chemical; & Structural

TECHNICAL SUMMARY: Chemical substitutions that increase the compositional complexity of the perovskite structure are known to give rise to properties that cannot be realized in simpler materials. However, as the compositional complexity increases detailed knowledge of the bonding interactions that drive atoms to assemble into homogeneous single phase materials is needed to rationally approach the synthesis and design of such materials. The proposed research involves synthesis of new perovskites and the use of advanced structural characterization tools, and property measurements to study these materials. The specific research objectives involve: (1) Synthesis and characterization of new perovskites with useful dielectric, magnetic and ionic conduction properties by simultaneously ordering A- and B-site cation arrays. (2) Studies of perovskites where octahedral tilting disrupts the corner sharing connectivity of the octahedral framework. (3) Studies of phase transitions in oxyfluoride double perovskite, coupled with use of cation bonding preferences to control the orientational ordering of anionic oxyfluoride polyhedra. Variable temperature Raman spectroscopy studies will be used to follow changes in local and long range structure that occur in response to changes in temperature or composition. New materials with attractive dielectric, magnetic, nonlinear optical and electrical properties are anticipated. NON-TECHNICAL SUMMARY: Perovskite materials play a central role in many important technologies including: dielectric materials for electronic applications, ion conductors for batteries and fuel cells, superconductivity and magnetoresistance to name a few. This grant will advance our understanding of how to control atomic scale ordering of elements to produce new materials for these important technologies. The research involves collaborations with internationally renowned electron microscopy centers in Australia and Spain. To disseminate this knowledge Web based resources will be developed that will positively impact teaching and research across several disciplines. An upper level laboratory experiment that teaches the principles of X-ray powder diffraction and crystal packing forces will be created, implemented and disseminated. Finally the project will provide important opportunities for graduate and undergraduate students to learn skills that are needed for modern materials chemistry research. Students will create important contacts through national and international collaborations supported by this project.

技术摘要：已知增加钙钛矿结构组成复杂性的化学替换会引起无法在简单材料中实现的特性。但是，随着组成复杂性增加了对键合的相互作用的详细知识，这些相互作用驱动原子聚集成均匀的单相材料，以合理地处理此类材料的综合和设计。 拟议的研究涉及合成新的钙钛矿以及使用先进的结构表征工具以及研究这些材料的财产测量。 特定的研究目标涉及：（1）通过同时订购A-和B点阳离子阵列，具有有用的介电，磁性和离子传导性能的新钙化物的合成和表征。 （2）对八面体倾斜的钙壶研究破坏了八面体框架的连通性的角落。 （3）对氧氟化双钙钛矿中的相变的研究，再加上阳离子粘结偏好来控制阴离子氧氟化物多面体的定向排序。 可变温度拉曼光谱研究将用于遵循响应温度或成分变化而发生的局部和远距离结构的变化。预计具有有吸引力的介电，磁性，非线性光学和电气性能的新材料。非技术摘要：钙钛矿材料在许多重要技术中起着核心作用，包括：用于电子应用的电介质材料，电池和燃料电池的离子导体，超导性和磁性耐药性等。 这笔赠款将促进我们对如何控制元素的原子规模排序的理解，以为这些重要技术生成新材料。该研究涉及与澳大利亚和西班牙国际知名的电子显微镜中心的合作。为了传播这些知识，将开发基于网络的资源，将对几个学科的教学和研究产生积极影响。 将创建，实施和传播一个教授X射线粉末衍射和晶体堆积力原理的上层实验室实验。 最后，该项目将为研究生和本科生提供重要的机会，以学习现代材料化学研究所需的技能。 学生将通过该项目支持的国家和国际合作建立重要的联系。