CAS: Design and discovery of lead-free hybrid layered perovskite dielectrics

CAS：无铅混合层状钙钛矿电介质的设计和发现

• 批准号: 2003793
• 负责人: Patrick Woodward
• 金额: $ 43.53万
• 依托单位: Ohio State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-06-01 至 2024-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2003793&HistoricalAwards=false
• 关键词: CAS; Design; discovery; lead; free

Non-Technical Abstract:Dielectric materials find widespread application in modern society. Ferroelectrics are used to make circuit elements such capacitors, antennas and filters; piezoelectrics are used in sonar and ultrasound imaging technologies; pyroelectrics are used in infrared imaging devices among other applications. The vast majority of dielectric materials are inorganic oxides, many of which contain lead. With support from the Solid State and Materials Chemistry Program and the Electronic and Photonic Materials Program in the Division of Materials Research the principle investigator and his group discover and develop new dielectric materials within the emerging family of hybrid layered perovskites, materials that are made up of alternating layers of positively charged organic cations and negatively charged, corner-connected metal-halide octahedra. Through an iterative program of synthesis and characterization the rules governing the complex crystal chemistry of these materials are studied. The new knowledge is then used to design new dielectric and magnetic materials that can serve as alternatives to the lead-based oxide dielectrics that are widely used today. In addition, authentic in-class research experiments are developed and implemented in general chemistry courses at Ohio State University that impact hundreds of students per year, introducing them to research and key materials chemistry concepts at an early stage of their college education. Finally, the graduate and undergraduate students supported by this project gain training that prepares them for successful careers in academia and industry. Technical Abstract:The research, supported by the Solid State and Materials Chemistry Program and the Electronic and Photonic Materials Program in the Division of Materials Research, can be divided into two thrust areas. The first thrust involves synthesis and characterization of layered double perovskites that contain a checkerboard pattern of 1+ and 3+ cations on the octahedral sites of the inorganic layers. When paired with the appropriate organic cations these materials are able to mimic the promising dielectric properties that have recently been seen in lead-based hybrid layered perovskites, while avoiding incorporation of toxic elements such as lead and cadmium. Phase transitions are studied to understand the structure directing forces in these materials and reveal the mechanisms by which various distortion mechanisms couple to one another. The second thrust brings a similar approach to compounds that contain magnetic cations, like Cu2+, Mn2+ and Fe2+. The research leverages the interactions between organic and inorganic layers to amplify the electrical polarization seen in polar crystals and enhance the coupling between magnetic and ferroelectric order parameters. The overarching theme of the research program is to develop an understanding of the complex crystal chemistry of these hybrid materials and use that knowledge to design and develop new ferroelectrics, antiferroelectrics, piezoelectrics, multiferroics, ferroelectric semiconductors, and related classes of multifunctional dielectric materials.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

非技术摘要：介电材料在现代社会中发现了广泛的应用。铁电器用于使电容器，天线和过滤器等电路元素。压电用于声纳和超声成像技术； pyroelectrics在红外成像设备和其他应用中都使用。绝大多数介电材料是无机氧化物，其中许多含有铅。在材料研究部的固态和材料化学计划以及电子和光子材料计划的支持下，原理研究者及其小组在新兴的混合分层perovskites家族中发现并开发了新的介电材料，这些材料由正面充电的有机阳离子的交替层组成，并具有负电荷的有机阳离子和负电荷的，负电荷的，带负电荷的，拐角孔连接的金属Halennected Metal-Halenected octhahelideRa。通过迭代的合成和表征程序，研究了这些材料复杂晶体化学的规则。然后，新知识用于设计新的电介质和磁性材料，这些介质和磁性材料可以用作当今广泛使用的铅基氧化物介电。此外，在俄亥俄州立大学的一般化学课程中开发和实施了真实的课堂研究实验，该课程每年影响数百名学生，并在大学教育的早期阶段将他们引入研究和关键材料化学概念。最后，该项目获得培训的研究生和本科生的支持，这为他们为学术界和行业的成功职业做好了准备。技术摘要：这项研究在材料研究部中的固态和材料化学计划以及电子和光子材料计划的支持下，可以分为两个推力区域。第一个推力涉及在无机层的八面体位点上包含1+和3+阳离子的棋盘格模式的分层双钙晶的合成和表征。当与适当的有机阳离子配对时，这些材料能够模仿有前途的介电特性，这些特性最近在铅基杂交层钙壶中看到，同时避免掺入诸如铅和镉之类的有毒元素。 研究了相变，以了解这些材料中的结构导向力，并揭示各种失真机制彼此之间的机制。第二个推力为包含磁阳离子（例如Cu2+，Mn2+和Fe2+）的化合物带来了类似的方法。该研究利用有机层和无机层之间的相互作用来扩增极性晶体中看到的电偏振，并增强磁和铁电量参数之间的耦合。研究计划的总体主题是对这些杂种材料的复杂晶体化学发展进行理解，并利用这些知识来设计和开发新的铁电材料，抗​​体电这些，压电，压电，多效性，多手感，铁电气，铁电极半导体，使用多功能介导材料的相关类别的相关类别。基金会的智力优点和更广泛的影响审查标准。

项目成果

Exploring the Stability of Mixed-Halide Vacancy-Ordered Quadruple Perovskites

• DOI: 10.1021/acs.chemmater.0c04951
• 发表时间: 2021-03-12
• 期刊: CHEMISTRY OF MATERIALS
• 影响因子: 8.6
• 作者: Gray, Matthew B.;Majher, Jackson D.;Woodward, Patrick M.
• 通讯作者: Woodward, Patrick M.

Exploring the AgSb1−xBixI4 phase diagram: Thermochromism in layered CdCl2-type semiconductors

• DOI: 10.1016/j.jssc.2021.121997
• 发表时间: 2021-05
• 期刊: Journal of Solid State Chemistry
• 影响因子: 3.3
• 作者: M. Gray;Eric T. McClure;N. Holzapfel;Felipe Pacci Evaristo;W. Windl;P. Woodward