CAREER: Ligand Engineering of Structure and Electronic Function in Complex Metal Oxyfluorides

职业：复杂金属氟氧化物结构和电子功能的配体工程

• 批准号: 1454688
• 负责人: James Rondinelli
• 金额: $ 50万
• 依托单位: Northwestern University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-06-01 至 2021-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1454688&HistoricalAwards=false
• 关键词: CAREER; Ligand; Engineering; Structure; Electronic

NON-TECHNICAL SUMMARYThe CAREER project supports computational materials science research and education aimed at understanding and designing electronic properties of materials, including electrical resistivity and optical behavior, by control over material structure at the level of atoms. The specific compounds of interest include oxides with transition metal cations, and focus on the effect that fluorine, which can substitute for oxygen in the materials, has on the electronic functionality. Previous research on transition metal oxides has established the importance of atomic structure engineering of electronic responses in many crystal families. Most conventional property-by-design routes rely, however, on changing the transition metal cation in oxides. This project seeks to apply another route - tuning the interactions in the crystal through anion (fluorine and oxygen) substitution. Changes in the geometry, arrangement and composition of the anion atoms will be explored through a confluence of materials theory techniques based on symmetry analyses, materials informatics (machine learning), and quantum mechanical calculations. The PI has ongoing collaborations with leading experts in synthesis and characterization of such materials composed of transition metals, oxygen, and fluorine; understanding derived here will stimulate experimental methods and vice versa. Continued investigation of known materials, while valuable, is inadequate to formulate strategies for deterministic property control. Knowledge obtained here will facilitate the selection and design of materials with tunable electronic states. It will benefit society by advancing the repertoire of structure-based design strategies to control electronic structure, which could lead to the discovery of new functional materials, e.g. for better performing energy storage and conversion systems, materials for transparent electronics, and optical technologies relying on laser generated light.This project will further the educational opportunities of students at Northwestern University and other academic institutions, precollege students, and contribute to the professional development of high school teachers. The PI will implement an educational plan to foster awareness, understanding, and appreciation of advanced technology materials and data-driven scientific methods through two main tasks. First, he will create Engineering Design Modules capable of engaging students in grades 9 through 12 by fostering model building skills to analyze and communicate concepts taught in secondary chemistry and physics courses that underpin many modern technologies, and support teachers preparing for the recently adopted Next Generation Science Standards. Second, he will create a Materials Informatics Curriculum to engage university students in modern informatics-based science problem-solving methods. All contextual learning activities will build knowledge, promote scientific and engineering literacy, and provide greater insight into the societal needs for engineering solutions, fostering cognitive skills through an emphasis on cause/effect relationships that are axiomatic to the research objectives and vital to the next-generation workforce. Assessment of the proposed educational activities and broad dissemination through multiple platforms will determine the efficacy of the educational activities, improve their implementation, and maximize impact.TECHNICAL SUMMARYThis CAREER award supports synergistic research, education, and outreach activities which focus on the design of functional electronic behavior in transition metal oxyfluorides using control over the ligand sublattice by oxygen/fluorine substitution and ordering. Conventional routes to direct the responses in transition metal oxides primarily rely on cation substitution and interfacial effects in thin films and superlattices, which offer limited control owing to a single (oxygen) anion - this makes materials discovery challenging. Remarkably, ligand (anion) engineering with mixed anion polyhedral building blocks remains to be fully exploited for property control and design, especially in these materials which already find use in energy generation and storage, phosphors, and catalysis. Combinations of applied group theory, informatics, and density functional theory calculations will be applied to achieve the main research objectives, which include (1) Advancing new theoretical methods to establish structure-function axioms for how anion order can be used to direct crystal structure and properties; (2) Formulating a quantitative theory of structure stability based on understanding the ligand sublattice symmetry and local bonding interactions; and (3) Understanding the consequences of mixed-anion polyhedral topologies on electronic properties. Structure-property axioms will be extracted by studying the consequences of anion substitution using oxyfluoride building blocks on physical properties in cryolite and elpasolite structures. With that knowledge, quantitative guidelines will be constructed to tailor electronic structure and properties in new oxyfluorides: metal-insulator transitions, electronic band gaps, and large non-linear optical responses. Success in this research will produce new knowledge underlying crystal stability, chemical bonding, and electronic behavior. It will articulate predictive rules for selecting new oxyfluorides, accelerate discovery, and enable an unprecedented expansion of compounds with varying electronic functions. Ultimately, interactions with experimental groups will lead to the discovery of functional properties in structurally and chemically more complex (hybrid) organic and inorganic materials than those proposed. Such collaborations will ensure that the virtual predictions translate into realistic models and new materials, which may transform the discovery process for materials deployed in glasses, phosphors, fuel-conversion, and Li-ion batteries technologies.This project will further the educational opportunities of students at Northwestern University and other academic institutions, precollege students, and contribute to the professional development of high school teachers. The PI will implement an educational plan to foster awareness, understanding, and appreciation of advanced technology materials and data-driven scientific methods through two main tasks. First, he will create Engineering Design Modules capable of engaging students in grades 9 through 12 by fostering model building skills to analyze and communicate concepts taught in secondary chemistry and physics courses that underpin many modern technologies, and support teachers preparing for the recently adopted Next Generation Science Standards. Second, he will create a Materials Informatics Curriculum to engage university students in modern informatics-based science problem-solving methods. All contextual learning activities will build knowledge, promote scientific and engineering literacy, and provide greater insight into the societal needs for engineering solutions, fostering cognitive skills through an emphasis on cause/effect relationships that are axiomatic to the research objectives and vital to the next-generation workforce. Assessment of the proposed educational activities and broad dissemination through multiple platforms will determine the efficacy of the educational activities, improve their implementation, and maximize impact.

非技术摘要职业项目支持计算材料科学研究和教育，旨在通过控制原子水平的材料结构来理解和设计材料的电子特性，包括电阻率和光学行为。感兴趣的具体化合物包括具有过渡金属阳离子的氧化物，并重点关注氟（可以替代材料中的氧）对电子功能的影响。先前对过渡金属氧化物的研究已经确立了许多晶体家族中电子响应的原子结构工程的重要性。然而，大多数传统的性能设计途径依赖于改变氧化物中的过渡金属阳离子。该项目寻求应用另一条途径——通过阴离子（氟和氧）取代来调节晶体中的相互作用。将通过基于对称分析、材料信息学（机器学习）和量子力学计算的材料理论技术的融合来探索阴离子原子的几何形状、排列和组成的变化。 PI 与领先专家持续合作，研究由过渡金属、氧和氟组成的此类材料的合成和表征；这里得出的理解将激发实验方法，反之亦然。对已知材料的持续研究虽然有价值，但不足以制定确定性属性控制的策略。这里获得的知识将有助于选择和设计具有可调谐电子态的材料。它将通过推进基于结构的设计策略来控制电子结构，从而造福社会，这可能会导致新功能材料的发现，例如性能更好的能量存储和转换系统、透明电子材料以及依赖激光产生光的光学技术。该项目将进一步增加西北大学和其他学术机构学生、大学预科生的教育机会，并为学生的专业发展做出贡献高中教师。 PI 将实施一项教育计划，通过两项主要任务来培养对先进技术材料和数据驱动的科学方法的认识、理解和欣赏。首先，他将创建工程设计模块，通过培养模型构建技能来分析和交流支撑许多现代技术的中学化学和物理课程中教授的概念，从而吸引 9 至 12 年级的学生，并支持教师为最近采用的下一代做好准备科学标准。其次，他将创建材料信息学课程，让大学生学习基于现代信息学的科学问题解决方法。所有情境学习活动都将积累知识，提高科学和工程素养，并更深入地了解工程解决方案的社会需求，通过强调因果关系来培养认知技能，这些关系对于研究目标来说是不言而喻的，并且对下一步至关重要。一代劳动力。对拟议的教育活动的评估和通过多个平台的广泛传播将决定教育活动的有效性，改善其实施并最大限度地发挥影响。技术摘要该职业奖支持协同研究、教育和推广活动，重点关注功能电子设计通过氧/氟取代和排序控制配体亚晶格，研究过渡金属氟氧化物的行为。指导过渡金属氧化物反应的传统途径主要依赖于薄膜和超晶格中的阳离子取代和界面效应，由于单一（氧）阴离子，这些效应提供的控制有限 - 这使得材料发现具有挑战性。值得注意的是，具有混合阴离子多面体结构单元的配体（阴离子）工程仍有待充分开发用于性能控制和设计，特别是在这些已用于能源产生和存储、磷光体和催化的材料中。将应用群论、信息学和密度泛函理论计算相结合来实现主要研究目标，其中包括（1）推进新的理论方法来建立结构函数公理，以说明如何使用阴离子顺序来指导晶体结构和特性; （2）基于对配体亚晶格对称性和局域键合相互作用的理解，制定结构稳定性的定量理论； (3) 了解混合阴离子多面体拓扑对电子特性的影响。通过研究使用氟氧化物构件进行阴离子取代对冰晶石和钾冰晶石结构的物理性质的影响，将提取结构-性质公理。有了这些知识，将构建定量指南来定制新型氟氧化物的电子结构和特性：金属-绝缘体跃迁、电子带隙和大的非线性光学响应。这项研究的成功将产生晶体稳定性、化学键合和电子行为的新知识。它将阐明选择新氟氧化物的预测规则，加速发现，并实现具有不同电子功能的化合物的前所未有的扩展。最终，与实验组的相互作用将导致发现结构和化学上比所提议的更复杂（混合）的有机和无机材料的功能特性。此类合作将确保虚拟预测转化为现实模型和新材料，这可能会改变玻璃、荧光粉、燃料转换和锂离子电池技术中使用的材料的发现过程。该项目将进一步增加学生的教育机会西北大学和其他学术机构的预科学生，并为高中教师的专业发展做出贡献。 PI 将实施一项教育计划，通过两项主要任务来培养对先进技术材料和数据驱动的科学方法的认识、理解和欣赏。首先，他将创建工程设计模块，通过培养模型构建技能来分析和交流支撑许多现代技术的中学化学和物理课程中教授的概念，从而吸引 9 至 12 年级的学生，并支持教师为最近采用的下一代做好准备科学标准。其次，他将创建材料信息学课程，让大学生学习基于现代信息学的科学问题解决方法。所有情境学习活动都将积累知识，提高科学和工程素养，并更深入地了解工程解决方案的社会需求，通过强调因果关系来培养认知技能，这些关系对于研究目标来说是不言而喻的，并且对下一步至关重要。一代劳动力。对拟议的教育活动进行评估并通过多个平台进行广泛传播将确定教育活动的有效性、改进其实施并最大限度地发挥影响。