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).

技术概述需要在微观和宏观水平上具有增强光学特性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、极性手征和手征结构，是晶体工程中一个正在进行的主题。这些材料对于修改光信号的振幅、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。八面体配位的过渡金属阳离子在混合金属氧化物中的八面体内畸变是不稳定的，这可以通过二级Jahn-Teller定理来理解。本课程探讨以非中心过渡金属氟氧化物为基础的非中心对称结构的研究。这些材料将提供一个大的和新的一类固体与压电性，热电性，铁电性和二次谐波产生（SHG），所有的属性与非中心对称空间群相关的属性。这项工作是由资助的固态和材料化学计划在材料Research.Non-technical SummaryThe合理的设计结构的基础上的化学性质的分子组成部分，一个长期的和令人兴奋的研究课题，在有机固态化学，是一个新兴的主题晶体工程。然而，需要具有增强的光学特性的高性能非线性光学（NLO）材料的技术依赖于表现出大的光学非线性的无机材料。缺乏反转对称性的结构是在过去二十年中由许多发明创造的重要的当前和未来技术的要求。这些材料提供了一个大的和新的一类固体在基础科学的研究与非中心对称空间群。我们提出了一个探索性的研究计划，对这些材料，这是突出最近在一篇题为“中国的水晶缓存”（自然2009年，457，953-955）。在这篇《自然》杂志的文章中，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。这项工作得到了国家科学基金会材料研究部固态和材料化学计划（DMR-1005827）的资助。