Excellence in Research - Exploring Frontiers in Novel Material Synthesis at High Pressures: Synthesis and Recovery of Superhard and High Energy-Density Polynitrides

卓越研究 - 探索高压新型材料合成前沿：超硬和高能量密度聚氮化物的合成和回收

• 批准号: 2200670
• 负责人: Mohammad Mahmood
• 金额: $ 49.87万
• 依托单位: Howard University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-07-01 至 2025-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2200670&HistoricalAwards=false
• 关键词: Excellence; Research; Exploring; Frontiers; Novel

Non-technical summary: Applying high pressure drastically changes physical and chemical properties of elements and compounds, which leads to the formation of fascinating new materials with unmatched properties. With support from NSF’s Office of Integrative Activities, researchers at Howard University and Carnegie Institution of Washington investigate nitrogen-rich metal compounds that form polymeric structures or large molecules (polynitrides) under high pressure. These materials show great promise as possible next-generation superhard or high-energy-density materials. The researchers explore the formation of specific alkali, alkali-earth and transition metal polynitrides at high-pressures and temperatures. Then they establish the material’s crystal chemistry and physical properties using a combination of laser-heated diamond anvil cells, synchrotron X-ray diffraction and Raman scattering experiments to tune the pressure-temperature conditions of synthesis and to probe the structure, physical properties, and chemical bonding of novel polynitrogen compounds. This research could aid and direct the functional design of new polynitrogen compounds with industrially relevant properties in the future. The project advances the Materials Science field in the search for new materials with potential energy applications as well as adjacent fields in Earth and Planetary sciences, which would benefit from better knowledge of crystal chemistry at extreme conditions. The project provides support and training to one postdoctoral associate at Howard University/Carnegie Institution for Science and advanced facilities (e.g. Advanced Photon Source, APS), as well as research opportunities for graduate and undergraduate students at Howard University. High school students will be engaged through a summer apprenticeship program.Technical summary: Material properties are greatly altered at high pressures, where unusual chemical bonding schemes and novel stoichiometries become thermodynamically stable. With support from NSF’s Office of Integrative Activities, researchers at Howard University and Carnegie Institution of Washington study the formation of alkali, alkali-earth and transition metal polynitrides (with focus on Li, K, Re, Os, W, Cr, Ru, Ti, Zr, Hf) at high-pressure high-temperature conditions, and their crystal chemistry and physical properties. The researchers exploit pressure as a tool to create a variety of unusual chemical bonding schemes and compositions, which become thermodynamically stable at high densities, but can be metastable at ambient pressure. Using a combination of X-ray diffraction and Raman experiments in laser-heated diamond anvil cell the researchers build a basis for further scaling-up of the synthesis, and reveal relations between synthesis conditions, chemical bonding, structure, and properties of polynitrides of different metals. This enables them to formulate crystal chemical principles governing the formation and behavior of polynitrides at extreme conditions. Furthermore, the researchers manipulate chemical composition, external strain, dimensionality, temperature, and chemical precursors as key variables that can be used to perform synthesis in the pressure-temperature range suitable for practical application and for metastable recovery of the 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：施加高压会大大改变元素和化合物的物理和化学特性，从而形成具有无与伦比的特性的迷人新材料。在NSF综合活动办公室的支持下，霍华德大学的研究人员和华盛顿的卡内基研究人员研究了在高压下形成聚合物结构或大分子（多硝酸盐）的富含氮的金属化合物。这些材料表现出巨大的前景，作为下一代超智或高能密度材料。研究人员探索了在高压和温度下的特定碱，碱产量和过渡金属多硝酸盐的形成。然后，他们使用激光加热的钻石砧细胞，同步加速器X射线衍射和拉曼散射实验的结合来建立材料的晶体化学和物理性质，以调整合成的压力温度条件，并探测新型多诺植物的结构，物理特性和化学性质的结构，物理性能和化学键合。这项研究可以帮助和指导新的多元氮化合物的功能设计，并在未来具有与工业相关的特性。该项目在寻找具有势能应用的新材料以及地球和行星科学领域的材料科学领域，这将受益于在极端条件下对晶体化学的更好知识。该项目为霍华德大学/卡内基科学与高级设施学会（例如高级光子来源，APS）的一位博士后助理提供支持和培训，以及霍华德大学研究生和本科生的研究机会。高中生将通过夏季学徒计划进行订婚。技术摘要：在高压下，材料特性发生了很大变化，在高压下，异常的化学粘合方案和新颖的化学构造在热力学上稳定。在NSF综合活动办公室的支持下，霍华德大学和华盛顿卡内基研究人员研究了碱，碱性和过渡金属多硝酸盐的形成（侧重于LI，K，RE，RE，OS，W，W，CR，CR，CR，RU，RU，RU，TI，TI，TI，ZR，HF）在高压力的高体质条件下以及其Cyrystal Chermalties及其晶体质量。研究人员将压力探索为创建各种异常化学键合方案和组成的工具，这些方案在高密度下在热力学上变得稳定，但在环境压力下可能是可稳定的。研究人员结合了激光加热的钻石砧细胞中X射线衍射和拉曼实验的组合，为进一步扩大合成的基础，并揭示了合成条件，化学键合，结构和特性之间的关系。这使他们能够制定晶体化学原理，以控制极端条件下多硝酸盐的形成和行为。 Furthermore, the researchers manipulate chemical composition, external strain, dimensionality, temperature, and chemical precursors as key variables that can be used to perform synthesis in the pressure-temperature range suitable for practical application and for metastable recovery of the materials.This award reflects NSF's statutory mission and has been deemed precious of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

项目成果

High-pressure phase of cold-compressed bulk graphite and graphene nanoplatelets

• DOI: 10.1103/physrevb.107.184102
• 发表时间: 2023-05
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: I. Efthimiopoulos;E. Stavrou;K. Umemoto;S. Mayanna;A. Torode;Jesse S. Smith;S. Chariton;V. Prakapenka;A. Goncharov;Yuejian Wang