Dense Solid Mixtures to Multifunctional Hybrid Carbon/Low Z Networks

非技术摘要：宇宙中的大多数物质都经历着高压和高温的极端条件，这些条件存在于行星和恒星的深处。在这样的条件下，第一和第二行（或低Z）元素固体，虽然在环境条件下作为简单的分子或元素固体存在，但形成不寻常的和高度致密的网络结构。这些材料非常坚硬，具有高能量密度，并表现出新颖的光学和电子特性。这些新的性质产生于集体行为的三维网络结构的低Z元素具有高的声子频率，热导率，内聚能，和强的电子-声子耦合。因此，这些密集堆积的低Z固体的结构和性质可以被视为自然界的窗口，以探索金刚石和过渡金属化合物以外的新结构和性质。然而，这些物质通常是在巨大的压力下形成的，在正常条件下可能不稳定;只有少数系统被恢复，将材料限制在基础科学发现的范围内。因此，一个令人兴奋的新的研究领域已经出现在理解，并最终控制的稳定性，键合，结构和性能的低Z扩展solids.Technical摘要：该项目旨在开发多功能的混合碳/低Z扩展固体适合稳定在环境条件下通过动力学控制过程中的异质固体mixtures。最先进的动态金刚石砧室实验加上时间分辨的拉曼和同步辐射X-射线表征被用来探测亚稳态界面结构，并利用内部化学压力和动态剪切的存在下，从而降低外部过渡压力，同时提高两个不喜欢的固体之间的相容性。通过科学发现和创新材料开发，该项目阐明了高压化学的基本原理，并展示了混合碳/低Z骨架材料在储氢、化学能储存以及非线性光学和电子应用方面的革命性能力。该项目还为研究生和本科生提供了重要的动手机会，在我们的机构，在同步加速器和中子设施，并在国家实验室学习实验技术。由于这项工作的多学科性质，这些学生正在获得固体化学，凝聚态物理学，材料和行星科学的许多学科的基础知识。

Nontechnical Abstract:Most materials in the universe experience extreme conditions of high pressure and high temperature, which exist deep in the planets and stars. Under such conditions, first- and second-row (or low Z) elemental solids, while existing as simple molecular or elemental solids at ambient conditions, form unusual and highly dense network structures. These materials are extremely hard, have high energy density, and exhibit novel optical and electronic properties. These novel properties arise from collective behaviors of 3D network structures of low Z elements with high phonon frequencies, thermal conductivities, cohesive energies, and strong electron-phonon couplings. The structures and properties of these densely packed low Z solids, therefore, can be viewed as nature's windows to unexplored novel structures and properties beyond those of diamond and transition metal compounds. However, these materials are often formed at formidable pressures and may be unstable at normal conditions; only a few systems have been recovered, limiting the materials within a realm of fundamental scientific discoveries. Therefore, an exciting new research area has emerged on understanding and, ultimately, controlling the stability, bonding, structure, and properties of low Z extended solids.Technical Abstract:This project aims to develop multifunctional hybrid carbon/low-Z extended solids amenable to stabilization at ambient conditions via kinetically controlled processes in heterogeneous solid mixtures. State of the art dynamic-diamond anvil cell experiments coupled with time-resolved Raman and synchrotron X-ray characterization are used to probe metastable interfacial structures and exploit the presence of internal chemical pressure and dynamic shears, thereby lowering the external transition pressure while enhancing the miscibility between two dislike solids. Through scientific discoveries and innovative material developments, the project elucidates the fundamental principles of high-pressure chemistry and demonstrate the revolutionary capabilities of hybrid carbon/low Z framework materials for hydrogen storage, chemical energy depository, and nonlinear optical and electronic applications. The project also provides graduate and undergraduate students with significant hands-on opportunities to learn experimental technologies at our institution, at the synchrotron and neutron facilities, and in national laboratories. Because of the multidisciplinary nature of this effort, these students are gaining fundamental knowledge across many academic disciplines of solid-state chemistry, condensed matter physics, and materials and planetary sciences.