Solid State Oxyfluorides

固态氟氧化物

• 批准号: 1005827
• 负责人: Kenneth Poeppelmeier
• 金额: $ 39万
• 依托单位: Northwestern 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: 2010-07-01 至 2013-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1005827&HistoricalAwards=false
• 关键词: Solid; State; Oxyfluorides

Technical SummaryTechnologies that require high-performance nonlinear optical (NLO) materials with enhanced optical properties at the microscopic and macroscopic level depend on inorganic materials that exhibit large optical nonlinearities (possessing a dipole). The rational design of crystal structures, in particular noncentrosymmetric materials, and how to differentiate polar, polar-chiral, and chiral structures, is an ongoing theme in crystal engineering. These materials are essential for the modification of the amplitude, phase, or frequency of an optical signal. Polar distortions in metal centered octahedra are the origin of the nonlinear optical response in metal oxides. Octahedrally coordinated transition metal cations in groups 4,5,6 are unstable in mixed metal oxides with respect to intraoctahedral distortions, which can be understood through the second order Jahn-Teller theorem. This program explores research on noncentrosymmetric structures based on acentric transition metal oxyfluorides. These materials will provide a large and new class of solids with properties associated with piezoelectricity, pyroelectricity, ferroelectricity and second harmonic generation (SHG), all properties associated with noncentrosymmetric space groups. This work is supported by a grant from the Solid State and Materials Chemistry Program in the Division of Materials Research.Non-technical SummaryThe rational design of structures based on the chemical nature of molecular components, a longstanding and exciting research topic in organic solid-state chemistry, is an emerging theme of crystal engineering. Technologies that require high-performance nonlinear optical (NLO) materials with enhanced optical properties, however, depend on inorganic materials that exhibit large optical nonlinearities. Structures lacking inversion symmetry are a requirement for important current and future technologies that have been created by numerous inventions during the past two decades. These materials provide a large and new class of solids for studies in basic science associated with the noncentrosymmetric space groups. We propose an exploratory research program on these materials, which were highlighted recently in an article entitled "China's Crystal Cache" (Nature 2009, 457, 953-955). In this Nature article the critical national need for synthesis-based efforts to discover and to grow suitable crystals of these new materials was emphasized. This work is supported by a grant from the Solid State and Materials Chemistry Program in the Division of Materials Research at the National Science Foundation (DMR-1005827).

技术综述需要在微观和宏观水平上增强光学性能的高性能非线性光学（NLO）材料的技术依赖于表现出大光学非线性（具有偶极子）的无机材料。晶体结构的合理设计，特别是非中心对称材料，以及如何区分极性、极性手性和手性结构，是晶体工程中一个不断发展的主题。这些材料对于改变光信号的幅度、相位或频率是必不可少的。金属中心八面体的极性畸变是金属氧化物非线性光学响应的根源。在混合金属氧化物中，基团4、5、6的八面体配位过渡金属阳离子在八面体内畸变方面是不稳定的，这可以通过二阶Jahn-Teller定理来理解。本课程探讨了基于无中心过渡金属氟氧化物的非中心对称结构的研究。这些材料将提供一种大型的新型固体，具有与压电性、热释电性、铁电性和二次谐波产生（SHG）有关的性质，所有这些性质都与非中心对称空间群有关。这项工作得到了材料研究部固态和材料化学项目的资助。基于分子组分化学性质的结构的合理设计是有机固体化学中一个长期而令人兴奋的研究课题，也是晶体工程的一个新兴主题。然而，需要具有增强光学性能的高性能非线性光学（NLO）材料的技术依赖于具有大光学非线性的无机材料。在过去的二十年中，许多发明创造了重要的当前和未来技术，缺乏反演对称的结构是这些技术的必要条件。这些材料为与非中心对称空间群相关的基础科学研究提供了大量的新型固体。我们提出了一个关于这些材料的探索性研究计划，最近在一篇题为“中国的水晶宝藏”的文章中强调了这一点（自然2009,457,953-955）。在这篇自然文章中，强调了国家迫切需要以合成为基础的努力来发现和生长这些新材料的合适晶体。本研究由美国国家科学基金会材料研究部固态与材料化学项目（DMR-1005827）资助。