Solid-State Oxides and Oxide-Fluorides

固态氧化物和氧化物-氟化物

• 批准号: 1307698
• 负责人: Kenneth Poeppelmeier
• 金额: $ 45万
• 依托单位: Northwestern University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-09-01 至 2017-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1307698&HistoricalAwards=false
• 关键词: Solid; State; Oxides; Oxide; Fluorides

TECHNICAL SUMMARYEmerging technologies require high-performance nonlinear optical (NLO) materials that exhibit enhanced optical properties at the microscopic and macroscopic level. The rational design of crystal structures, in particular noncentrosymmetric (NCS) materials, and how to target polar, polar-chiral, and chiral structures, is an ongoing theme in crystal engineering. A new class of potentially high performance NLO inorganic materials, solid-state oxide-fluorides, has been identified with the synthesis of new compounds containing [MOxF6-x]2- units in inorganic, solid-state environments. In the process it has been discovered that i) the use of fluoride ligands with early-transition metals (ETMs) enhances the second-order Jahn-Teller distortion in comparison to pure oxide ETM compounds, ii) the synthesis of NCS materials can be achieved with the use of polar basic-building units (BBUs), iii) design of NCS BBUs can predictably lead to NCS structures, iv) the synthesis of compounds that contain two, separate anionic BBUs is likely to result in an NCS compound, and v) the synthesis of ETM oxide-fluoride compounds can produce energy-storage materials such as high-potential primary batteries. Drawing from these learned principles, a program of discovery-based research on NCS structures based on acentric ETM oxide-fluorides (ETMOFs) is planned. These materials comprise a large and new class of solids with properties associated with piezoelectricity, pyroelectricity, ferroelectricity and second harmonic generation (SHG). The structural-property relationships that give rise to high, low, or null nonlinearities of the NLO material are examined. Finally, the growth of large crystals (on the order of 1 cm3) allows detailed analysis with measurements of the NLO tensor and phase-matchability properties, and other properties of interest such as piezoelectricity. The materials synthesized will have potential use in relaxor ferroelectrics and non-linear optics. These materials will have a high damage threshold and the potential for bulk growth to create large, single crystals suitable for optical use and examination. This work is supported by the Solid State and Materials Chemistry Program.NON TECHNICAL SUMMARYAs recently described in a Nature News Feature, the highly-efficient non-linear optical (NLO) oxide-fluoride material KBe2BO3F4 and other NLO materials are essential to act as wave guides for the modification of the amplitude, phase, and/or frequency of an optical signal. Such materials are used in femtosecond laser spectroscopy and-more recently-to generate UV laser light for nanolithography. Such NLO materials are increasingly needed to upconvert laser light to higher energies by second-harmonic generation (SHG). Current research and engineering activities in the field of NLO materials typically concern synthesis of NLO crystals; however, research is lacking in understanding how to design NLO materials and why materials exhibit a particular NLO response. While exploring the fundamental driving factors that create NLO materials, research will be performed to grow large (on the order of cm3) single crystals with a floating zone image furnace to allow a quantitative understanding of the interaction of light with the NLO material. This project concerns such analyses and progress made towards rational synthesis of solid-state inorganic materials and analysis of their structure-property relationships. These analyses of basic principles of the chemistry by graduate students and postdoctoral associates - who are engaged in local education, teaching, mentoring, and leadership - will facilitate broad understanding of stable solid-state compounds.

新兴技术需要高性能非线性光学（NLO）材料，其在微观和宏观水平上表现出增强的光学性质。晶体结构的合理设计，特别是非中心对称（NCS）材料，以及如何针对极性，极性手性和手性结构，是晶体工程中正在进行的主题。一类新的潜在的高性能NLO无机材料，固态氧化物-氟化物，已被确定为在无机固态环境中合成含有[MOxF 6-x]2-单元的新化合物。在该方法中，已经发现i）与纯氧化物ETM化合物相比，使用具有早过渡金属（ETM）的氟化物配体增强了二级Jahn-Teller畸变，ii）可以使用极性碱性构建单元（BBU）来实现NCS材料的合成，iii）NCS BBU的设计可以可预测地导致NCS结构，iv）合成含有两个，单独的阴离子BBU可能产生NCS化合物，和v）ETM氧化物-氟化物化合物的合成可以产生能量存储材料，例如高电位原电池。借鉴这些经验教训的原则，发现为基础的NCS结构的偏心ETM氧化物-氟化物（ETMOFs）的研究计划。这些材料包括一个大的和新的类别的固体与压电性，热电性，铁电性和二次谐波产生（SHG）的属性。的结构性能的关系，引起高，低，或零的非线性非线性光学材料进行检查。 最后，大晶体的生长（约1立方厘米）允许详细的分析与测量的非线性光学张量和相位匹配性能，以及其他感兴趣的属性，如压电。所合成的材料在弛豫铁电体和非线性光学方面具有潜在的应用价值。这些材料将具有高损伤阈值和体生长的潜力，以产生适合光学用途和检查的大单晶。这项工作得到了固态和材料化学计划的支持。非技术总结正如最近在自然新闻特写中所描述的那样，高效非线性光学（NLO）氧化物-氟化物材料KBe 2BO 3F 4和其他NLO材料对于作为波导来修改光信号的振幅、相位和/或频率是必不可少的。这种材料用于飞秒激光光谱学，最近用于产生纳米光刻的紫外激光。 这种NLO材料越来越需要通过二次谐波产生（SHG）将激光上转换为更高的能量。目前在NLO材料领域的研究和工程活动通常涉及NLO晶体的合成;然而，研究缺乏对如何设计NLO材料以及为什么材料表现出特定NLO响应的理解。在探索创建NLO材料的基本驱动因素的同时，将进行研究，以使用浮区成像炉生长大型（cm 3量级）单晶，从而定量了解光与NLO材料的相互作用。本计画系关于固态无机材料之合理合成及其结构与性质关系之分析与进展。研究生和博士后同事对化学基本原理的分析-他们从事当地的教育，教学，指导和领导-将促进对稳定固态化合物的广泛理解。