CAREER: An Elastic Approach to Strong Glasses

非技术描述：随着个人电子、汽车、太阳能电池板、建筑和海底通信电缆等应用对轻质耐用玻璃的需求不断增加，寻找坚固的玻璃是当今最重要的兴趣。本项目旨在通过实验研究玻璃对外界刺激（如温度和压力）的弹性响应，并辅以计算机模拟，提高对玻璃微观结构的基础知识。对玻璃结构的基本理解可以使玻璃的预测设计具有量身定制的特性，并在能源消耗和可持续性方面带来相关好处。综合教育计划是通过：1)在材料科学与工程课程中引入本科水平的计算材料科学课程；2)将计算模块纳入核心材料科学课程。在这个项目中，研究生和本科生在玻璃研究的前沿领域进行培训。通过激发年轻人的好奇心，培养对女性和少数族裔的信心，不断努力激励和鼓励K-12学生将科学和工程作为职业道路。技术细节：准确了解玻璃的原子结构对于实现玻璃科学技术的未来突破至关重要。然而，尽管研究广泛，在原子水平上表征玻璃的无序结构仍然是一个巨大的挑战。该项目解决了长期存在的问题，通过热或机械搅拌探测/扰动玻璃结构，从而导致其弹性模量的变化。这种外部刺激下的变化不可避免地反映了潜在的结构反应和结构本身。这种响应的产生是因为弹性模量与原子排列和原子间相互作用密切相关，体现了微观结构和键信息。弹性模量的定义简单，宏观上易于测量。对玻璃中结构-弹性模量关系的基本理解可以帮助我们理解最近在氧化物和金属玻璃中观察到的一个显著的经验相关性：即断裂能随着泊松比的增加而增加，在临界泊松比为0.31-0.32时，脆性向延性的急剧转变。同时，泊松比与断裂能之间的关系可以为寻找强玻璃提供指导。采用高温、高压、高应变条件下的原位拉曼和布里渊光散射技术，并辅以预测计算方法来完成本项目的研究目标。

NON-TECHNICAL DESCRIPTION: The search for strong glasses is of paramount interest today with the increasing demand for light-weight and durable glasses for applications such as personal electronics, automobiles, solar panels, buildings, and submarine communications cables. This project aims to advance fundamental knowledge of the microscopic structure of glass by studying its elastic response to external stimuli such as temperature and pressure in experiments complemented by computer simulations. A fundamental understanding of glass structure may enable predictive design of glasses with tailor-made properties and related benefits with respect to energy consumption and sustainability. The integrated educational plan is to address the computational materials science curriculum development by: 1) introducing an undergraduate level computational materials science course into the Materials Science and Engineering curriculum; and 2) incorporating computational modules into core materials science classes. In carrying out this project, graduate and undergraduate students are trained in frontier areas of glass research. Continuous efforts are being made to inspire and encourage K-12 students to pursue science and engineering as a career path, by igniting curiosity in young minds and instilling confidence in women and underrepresented minorities. TECHNICAL DETAILS: An accurate knowledge of the atomic structure of glass is critical for enabling future breakthroughs in glass science and technology. However, despite extensive research, characterizing the disordered structure of glass at the atomic level remains a grand challenge. This project tackles the longstanding problem by probing/perturbing the glass structure with thermal or mechanical agitations, which leads to variations in its elastic moduli. Such changes under external stimuli inevitably reflect the underlying structural response, and the structure itself. This response occurs because elastic moduli, simple to define and easy to measure macroscopically, are closely related to the atomic arrangements and the interatomic interactions, embodying the microscopic structure and bonding information. The fundamental understanding of the structure-elastic moduli relation in glass may help us to understand a striking empirical correlation observed recently in oxide and metallic glasses: namely that the fracture energy increases with the Poisson's ratio, with a sharp brittle-to-ductile transition at a critical Poisson's ratio of 0.31-0.32. At the same time, the correlation between Poisson's ratio and fracture energy can serve as a guide to search for strong glasses. In situ Raman and Brillouin light scattering techniques under high temperature, high pressure and high strain conditions, complemented by predictive computational methods, are used to accomplish the research goals of this project.