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.

技术摘要新兴技术需要高性能非线性光学 (NLO) 材料，这些材料在微观和宏观层面上表现出增强的光学特性。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，是晶体工程的一个持续主题。通过在无机固态环境中合成含有 [MOxF6-x]2- 单元的新化合物，已经确定了一类新的潜在高性能 NLO 无机材料，即固态氧化物氟化物。在此过程中，我们发现i）与纯氧化物ETM化合物相比，使用氟化物配体与早期过渡金属（ETM）增强了二阶Jahn-Teller畸变，ii）可以实现NCS材料的合成通过使用极性基本结构单元 (BBU)，iii) NCS BBU 的设计可以预见地导致 NCS 结构，iv) 可能会产生包含两个单独的阴离子 BBU 的化合物的合成v) ETM 氧化物-氟化物的合成可以生产储能材料，例如高潜力原电池。根据这些学到的原理，计划对基于无心 ETM 氧化物氟化物 (ETMOF) 的 NCS 结构进行基于发现的研究计划。这些材料由一大类新型固体组成，具有与压电、热电、铁电和二次谐波产生 (SHG) 相关的特性。研究了导致 NLO 材料的高、低或零非线性的结构-性能关系。 最后，大晶体（大约 1 cm3）的生长允许通过测量 NLO 张量和相位匹配特性以及其他感兴趣的特性（例如压电性）进行详细分析。合成的材料将在弛豫铁电体和非线性光学中具有潜在的用途。这些材料将具有高损伤阈值和体生长以产生适合光学使用和检查的大型单晶的潜力。这项工作得到了固态和材料化学计划的支持。非技术摘要正如最近在《自然》新闻专题中所描述的，高效非线性光学（NLO）氧化物氟化物材料 KBe2BO3F4 和其他 NLO 材料对于充当波至关重要用于修改光信号的幅度、相位和/或频率的指南。此类材料用于飞秒激光光谱学，最近还用于产生用于纳米光刻的紫外激光。 人们越来越需要这种 NLO 材料通过二次谐波产生 (SHG) 将激光上转换为更高的能量。当前 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，对于如何设计 NLO 材料以及为什么材料表现出特定的 NLO 响应缺乏研究。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图像炉生长大型（cm3 数量级）单晶，以便定量了解光与 NLO 材料的相互作用。该项目涉及固态无机材料的合理合成及其结构-性能关系分析的分析和进展。从事当地教育、教学、指导和领导的研究生和博士后对化学基本原理的分析将促进对稳定固态化合物的广泛理解。