New Fluoride and Oxyfluoride Materials – Targeting Magnetic and Optical Properties

含有不同化学元素的非技术材料表现出广泛的有用的日常性能，可以在像LED灯泡这样的基本设备中找到。这些特性包括光学和磁性行为，特别是在含有氟的材料中，并被用于许多需要发光才能发挥作用的应用。例子包括LED灯泡的涂层，国土安全的辐射探测器，以及医疗X光扫描仪。对于许多光学应用来说，获得单晶形式的材料是必要的。因此，在NSF材料研究部固态和材料化学计划的支持下，这项研究的目标是通过开发新的方法来生长新的氟化物材料的晶体，并通过优化化学成分来获得具有所需性能的材料。基础研究的重点是新的含氟材料的晶体生长，这些材料旨在表现出特定的性能，如发光，这可以得到广泛的应用，可以造福于国家。作为这项研究的一部分，通过让广泛的学生，包括那些来自代表不足的群体的学生，参加材料化学研究实验室的经历，对许多学生进行化学科学方面的培训。此外，针对本科生的暑期项目允许未被充分代表的少数族裔参与研究，并向他们传授材料化学知识，目的是专门招收他们进入南卡罗来纳大学的化学研究生项目。技术概述通过晶体生长发现材料的概念被应用于大幅增加新的氟化物和氟氧化物材料家族的数量，以开发新的功能材料。众所周知，复合氟化物材料对于依赖其光学性质的应用非常重要，例如发光和闪烁，而获得表现出磁性受挫的氟化物和氟氧化物结构的能力对于理解自旋-液体和自旋-冰行为是普遍感兴趣的。该研究项目的中心是开发新的方法，系统地合成和表征新型氟化物和氟氧化物材料，并研究它们的光学和磁性行为。具体来说，通过三种不同的合成路线(温和水热法、超临界水热法和助熔剂晶体生长法)对新型氟化物和氟氧化物材料的晶体生长进行了优化，以生产新的磁性和光学材料。通过选择过渡元素和稀土元素并将其加入到新的氟化物和氟氧化物结构中来控制性能，其中包含过渡和稀土金属的元素用于研究磁性，而包含镧系元素的元素用于研究光学性质。作为这项研究的一部分，通过让广泛的学生，包括那些来自代表不足的群体的学生，参加材料化学研究实验室的经历，对许多学生进行化学科学方面的培训。此外，一个面向本科生的暑期项目允许未被充分代表的少数群体参与研究，并向他们传授材料化学方面的知识，目标是专门招募他们进入南卡罗来纳大学的化学研究生课程。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Non-TechnicalMaterials containing different chemical elements exhibit a wide range of useful, everyday properties and are found in devices as basic as LED light bulbs. The properties, which include optical and magnetic behavior, are found especially in materials containing fluorine and are used for many applications that require the emission of light for them to function. Examples include coatings in LED light bulbs, radiation detectors for homeland security, and scanners for medical x-rays. For many optical applications it is necessary to obtain the materials in the form of single crystals. The research, supported by the Solid State and Materials Chemistry program in NSF’s Division of Materials Research, therefore, targets the crystal growth of new fluoride materials by developing new methods to grow such crystals and by optimizing the chemical compositions to obtain materials with the desired properties. The basic research focus is on the crystal growth of new fluorine-containing materials that are designed to exhibit specific properties, such as light emission, which can find widespread applications and can benefit the nation. As part of this research, numerous students are trained in the chemical sciences by involving a wide range of students, including those from underrepresented groups, in a materials chemistry research laboratory experience. Furthermore, a summer program for undergraduates allows the involvement of underrepresented minorities in research and teaches them about the chemistry of materials with the goal of recruiting them specifically into the University of South Carolina chemistry graduate program. Technical SummaryThe concept of materials discovery via crystal growth is applied to substantially increase the number of new fluoride and oxyfluoride material families to develop new functional materials. It is well known that complex fluoride materials are important for applications that rely on their optical properties, such as luminescence and scintillation, while the ability to obtain fluoride and oxyfluoride structures exhibiting magnetic frustration is of general interest for understanding spin-liquid and spin-ice behavior. The research project is centered around the development of new approaches to systematically synthesize and characterize new classes of fluoride and oxyfluoride materials and to study their optical and magnetic behavior. Specifically, the optimization of the crystal growth of new fluoride and oxyfluoride materials is carried out via three different synthetic routes (mild hydrothermal, supercritical hydrothermal, and flux crystal growth) to produce new magnetic and optical materials. Properties are controlled via the selection and incorporation of transition and lanthanide elements into the new fluoride and oxyfluoride structures, where those containing transition and lanthanide metals are used to study magnetic behavior and those containing lanthanides are used to study optical properties. As part of this research, numerous students are trained in the chemical sciences by involving a wide range of students, including those from underrepresented groups, in a materials chemistry research laboratory experience. Furthermore, a summer program for undergraduates allows the involvement of underrepresented minorities in research and teaches them about the chemistry of materials with the goal of recruiting them specifically into the University of South Carolina chemistry graduate program.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.