Metallization of Hydrogen-Rich Materials: Predicting Novel Superconductors

富氢材料的金属化：预测新型超导体

• 批准号: 1005413
• 负责人: Eva Zurek
• 金额: $ 38万
• 依托单位: SUNY at Buffalo
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-15 至 2014-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1005413&HistoricalAwards=false
• 关键词: Metallization; Hydrogen; Rich; Materials; Predicting

TECHNICAL SUMMARYThe Division of Materials Research and the Office of Cyberinfrastrcture contribute funds to this award. It supports theoretical research and education which will lead towards the rational design of novel superconductors. It is thought that under sufficient compression hydrogen will become metallic due to the pressure-induced broadening of filled and unfilled bands, and their eventual overlap. Theoretical predictions indicate that this phase may be a high temperature superconductor. Unfortunately, hydrogen does not become metallic at the highest static pressures reached so far. There is now tremendous interest in developing chemically inspired strategies which could significantly decrease the pressure necessary for metallization. Two examples are: combination with tetravalent atoms, as in the group 14 hydrides, or by the addition of an electropositive element.The PI will focus on predicting the structures of ionic and covalent polyhydrides with unusual stoichiometries that are stable, and metallic under pressure. An evolutionary algorithm, interfaced with a first-principles electronic structure program will be employed towards this end. Already, theoretical and experimental research has shown that specific lithium and silicon bearing hydrogen materials become stable when squeezed, and it is likely that they are metals at experimentally achievable pressures. This work will lead to a deeper understanding of the chemistry, electronic structure and potential superconductivity of hydrogen-rich materials under pressure. The PI aims to determine which factors are important in facilitating the metallization of these systems under mild compression, determine the most favorable stoichiometries and structures, their properties, and ways to chemically stabilize these phases at commercially accessible pressures. The PI will develop an evolutionary algorithm, XtalOpt, which will be used to predict the structures of the most stable systems. This algorithm will be made freely available to the materials science, physics and chemistry communities as an extension to the free visualization tool "Avogadro." It will be released under the GNU Public License, and interfaced with several electronic structure packages which are widely used to study solids. The code will make use of already existing cyberinfrastructure, and will be highly modular, and clearly documented so as to facilitate further development.NONTECHNICAL SUMMARYThe Division of Materials Research and the Office of Cyberinfrastrcture contribute funds to this award. It supports theoretical research and education whose ultimate goal is to use concepts, and theoretical and computational techniques to design new superconducting materials. In a superconductor electric current can flow without dissipation. Replacing copper wires with high temperature superconducting power lines could have a tremendous impact on the electrical power infrastructure of the USA. Unfortunately, all of the materials which are known to behave as superconductors do so only at very low temperatures. Theoretical work has predicted that under pressure the simplest element hydrogen will become metallic, and superconducting near room temperature. Unfortunately, the pressures necessary to metalize hydrogen are greater than those at the center of the earth. The PI will develop chemically inspired strategies which could significantly decrease the pressure necessary to achieve metallic hydrogen. State-of-the-art computational techniques will be employed to predict the structures and properties of hydrogen rich systems under pressure. The PI's computations will determine if these materials could potentially be superconductors, and will suggest how these phases may be chemically stabilized at normal pressures. An evolutionary algorithm, XtalOpt, will be developed in order to predict the structures of the most stable systems. This algorithm will be made freely available to the materials science, physics and chemistry communities as an extension to the free visualization tool "Avogadro." It will be released under the GNU Public License, and interfaced with several computer programs which are widely used to study solid state materials.

技术摘要材料研究部和网络Frastrcture办公室为该奖项贡献了资金。它支持理论研究和教育，这将导致新型超导体的合理设计。人们认为，由于压力引起的填充和未填充的带的宽扩大以及它们的最终重叠，因此在足够的压缩氢下会变成金属。理论预测表明，这一阶段可能是高温超导体。不幸的是，到目前为止，在达到最高的静态压力下，氢不会变成金属。现在，人们对制定化学启发的策略有很大的兴趣，这些策略可能会大大降低金属化所需的压力。两个例子是：与四位价原子（如14组氢化物中）或通过添加电体元素的结合。PI将集中于预测具有稳定和金属在压力下具有不寻常稳定的离子和共价多水的结构。将采用与第一原理电子结构程序相连的进化算法。理论和实验研究已经表明，挤压时具有氢材料的特定锂和硅材料变得稳定，并且在实验性可实现的压力下它们很可能是金属。这项工作将导致对在压力下富含氢的材料的化学，电子结构和潜在超导性的深入了解。 PI旨在确定哪些因素对于在轻度压缩下促进这些系统的金属化，确定最有利的化学计量和结构，它们的特性以及在商业上可接触的压力下化学稳定这些阶段的方法很重要。 PI将开发一种进化算法Xtalopt，该算法将用于预测最稳定系统的结构。该算法将免费提供给材料科学，物理和化学社区，以扩展“ Avogadro”的免费可视化工具。它将在GNU公共许可证下发布，并与多个电子结构软件包相连，这些套件被广泛用于研究固体。 该守则将利用已经存在的网络基础设施，并将是高度模块化的，并有清晰的记录以促进进一步的开发。材料研究部和Cyber​​infrastrcture办公室的部门和Cyber​​infrastrcture办公室为该奖项贡献了资金。它支持理论研究和教育，其最终目标是使用概念以及理论和计算技术设计新的超导材料。在超导电流中，电流可以流动而不会耗散。用高温超导电源线代替铜线可能会对美国的电力基础设施产生巨大影响。不幸的是，所有被称为超导体行为的材料仅在非常低的温度下才能做到这一点。理论工作已经预测，在压力下，最简单的元素将变成金属，并在室温接近室温。不幸的是，金属化氢所需的压力大于地球中心的压力。 PI将制定化学启发的策略，这些策略可能会大大降低获得金属氢所需的压力。将采用最先进的计算技术来预测压力下富氢系统的结构和特性。 PI的计算将确定这些材料是否可能是超导体，并建议如何在正常压力下化学稳定这些相。为了预测最稳定系统的结构，将开发一种进化算法Xtalopt。该算法将免费提供给材料科学，物理和化学社区，以扩展“ Avogadro”的免费可视化工具。它将在GNU公共许可证下发布，并与多个计算机程序相连，这些计算机程序被广泛用于研究固态材料。