Ternary and Quaternary Nitrides

三元和四元氮化物

• 批准号: 0245462
• 负责人: Francis DiSalvo
• 金额: --
• 依托单位: Cornell University
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-06-01 至 2006-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0245462&HistoricalAwards=false
• 关键词: Ternary; Quaternary; Nitrides

The goal of this project is to explore the preparation of ternary and quaternary nitrides and determine their properties. As with oxide chemistry where ternaries and quaternaries offer a greater, more tunable, qualitatively different and more useful set of properties than the binaries, so too is it expected that ternary and quaternary nitrides will eventually provide the same since so many useful binary nitrides are known. Although structurally interesting compounds have been found, some with unusual properties, the study of such ternary and quaternary nitrides is still in its infancy, especially when compared to ternary and quaternary oxides, or even to sulfides, phosphides, carbides, etc. New synthetic techniques are being invented and exploited to prepare a wide variety of novel nitride compounds. Although there are only a few groups in the U.S. exploring the solid state chemistry of nitrides, it is a very active field of research in Europe and Japan. Close ties to many of those groups and this U.S. effort have resulted in programs for exchanging students and postdocs. This project will focus on the use of molten metals and their alloys as fluxes (solvents) to prepare conducting, possibly even superconducting, as well as magnetic multinary nitrides that will be examined for potential technological uses and for novel phenomena. Low melting point metals, such as sodium, zinc, gallium, indium, tin, and bismuth will be explored for this purpose. Initial results suggest that these fluxes and alloys of these fluxes will be highly useful for producing a large number of new compounds with novel structures and properties. This research will also be a vehicle for the training of undergraduates, graduate students and postdocs in the science and art of Solid State Chemistry. The results of this research will be widely disseminated via the WEB, publications, seminars, professional meetings and, where appropriate, via patents. Interactions with industry prompted by current findings are underway. The methodology and results have also been and will continue to be incorporated in undergraduate courses and especially in a graduate course on Solid State Chemistry developed by the PI. The PI and his research group are also very active in bringing science to a wide audience, including K - 12 school children, science teachers in middle and high schools as well as community colleges, and to undergraduates from smaller colleges and universities. The latter students do not otherwise have the opportunity to be involved in research at the forefront of materials chemistry or use the advanced instrumentation available at Cornell University. K - 12 students are reached through Chemistry Demonstrations that are performed in the local schools. Undergraduate students from smaller colleges and local high school teachers spend up to 10 weeks in the summer working in these laboratories. The entire community is reached by several local newspaper columns the PI has written for the Ask a Scientist weekly feature reaching 80,000 readers. These outreach activities are not only aimed at attracting a broad cross section of young people to science, but perhaps more importantly, they are an integral part of helping to develop a scientifically literate public. %%%There are already many important uses of binary nitrides. These include aluminum nitride (high thermal conductivity substrates), silicon nitride (as chemical vapor deposited coating on electronics, etc.), titanium nitride (hard coatings for tools), tantalum nitride (metallic conductors and diffusion barriers in electronics, colored surfaces in jewelry, artistic displays, etc.), niobium nitride (thin film super-conducting devices), gallium nitride (blue light emitting diodes, high speed - high power electronics). Is it expected that ternary and quaternary nitrides will eventually provide a whole new class of functional materials of high value to advancing new technologies. Students trained in these areas are very competitive for a wide range of jobs in the academic, industrial, and government laboratory sectors.

本计画的目标是探索三元及四元氮化物的制备方法并测定其性质。与氧化物化学一样，其中三元和四元化合物提供比二元化合物更大、更可调、性质上不同和更有用的一组性质，因此也预期三元和四元氮化物最终将提供相同的性质，因为已知如此多的有用的二元氮化物。 虽然结构有趣的化合物已被发现，一些具有不寻常的性能，这种三元和四元氮化物的研究仍处于起步阶段，特别是当相比，三元和四元氧化物，甚至硫化物，磷化物，碳化物等新的合成技术正在发明和利用，以制备各种各样的新型氮化物化合物。虽然在美国只有少数几个团体探索氮化物的固态化学，但在欧洲和日本，这是一个非常活跃的研究领域。与许多这些团体的密切联系以及美国的这一努力导致了交换学生和博士后的计划。 该项目将侧重于使用熔融金属及其合金作为助熔剂（溶剂）来制备导电，甚至可能超导，以及磁性多元氮化物，这些氮化物将被用于潜在的技术用途和新现象。为此目的，将探索低熔点金属，如钠、锌、镓、铟、锡和铋。初步结果表明，这些焊剂和这些焊剂的合金将是非常有用的，用于生产大量的新化合物具有新颖的结构和性能。 这项研究也将成为培养本科生，研究生和博士后在固态化学的科学和艺术的工具。这项研究的结果将通过网站、出版物、研讨会、专业会议以及适当的专利广泛传播。目前正在根据目前的调查结果与工业界进行互动。方法和结果也已经并将继续被纳入本科课程，特别是在固态化学研究生课程开发的PI。PI和他的研究小组也非常积极地将科学带给广泛的受众，包括K - 12学童，初中和高中以及社区学院的科学教师，以及来自较小学院和大学的本科生。后者的学生没有机会参与材料化学前沿的研究或使用康奈尔大学提供的先进仪器。K - 12学生通过在当地学校进行的化学演示达到。来自较小学院的本科生和当地高中教师在夏季在这些实验室工作长达10周。PI为《问科学家》周刊撰写的几篇当地报纸专栏文章覆盖了整个社区，读者达80，000人。 这些推广活动的目的不仅是吸引广大青年人参与科学，而且也许更重要的是，它们是帮助培养具有科学素养的公众的一个组成部分。二元氮化物已经有许多重要的用途。这些材料包括氮化铝（高导热性基底）、氮化硅（作为电子器件上的化学气相沉积涂层等）、氮化钛（用于工具的硬涂层），氮化钽（电子产品中的金属导体和扩散阻挡层，珠宝、艺术显示器中的彩色表面等），氮化铌（薄膜超导器件）、氮化镓（蓝光发光二极管、高速大功率电子器件）。预计三元和四元氮化物最终将提供一个全新的功能材料类别的高价值，以推进新技术。在这些领域接受培训的学生在学术，工业和政府实验室部门的广泛工作中非常有竞争力。