玻璃自古以来便被不断使用,当今仍然是人类生活中无处不在、不可或缺的最有价值材料之一.然而,由于玻璃态物质是一种与固体、液体不同的介稳态物质,处于复杂的多体相互作用体系,玻璃态物质的本质一直是凝聚态物理中最富挑战的谜题之一.Science在创刊125周年之际将"玻璃态物质的本质是什么"这一问题列为125个最具挑战性的科学前沿问题之一.本文综述了玻璃态转变过程中的热力学和动力学变化规律、玻璃态形成的物理机制和理论预测、玻璃态的结构假说等玻璃态物质研究的焦点和难点,讨论了当前的研究进展并展望未来的研究方向,以期增加人们对玻璃态物质本质的新认识,为玻璃态物质的后续研究提供借鉴.
Glasses, non-crystalline solids, and amorphous materials are presently playing increasingly important roles in modern technology. In addition to conventional glass, which is an indispensable material in the current economy in architecture, transport, lighting, and environmental control, a wide variety of glasses and amorphous materials are used in increasingly sophisticated applications in optics, electronics, optoelectronics, energy science and biotechnologies. Glass is considered a vitreous supercooled liquid that is in a thermodynamically metastable state between the molten liquid state and the crystalline state. This unique property of glass is different from the solid, liquid, and gaseous states observed for other elements. The vitrification of a liquid to form a glass is often related to glass transition. This process is a complex dynamic system with multi-body interactions, and hence glass transition is still an unsolved problem in condensed matter physics up to the present time. The formation of glasses is an extremely interesting phenomenon. In terms of thermodynamic phase equilibrium, no substance should persist in the glassy state because glass is a metastable state. However, in terms of kinetics, any material can form a glassy state as long as the cooling rate and the melting viscosity are sufficiently high to prevent crystallization. A comprehensive understanding of the nature of glass formation and the factors that predominantly dominate the glass-forming ability and glass-forming regions of materials is of fundamental importance for advancing the technological applications of glasses. Glass structure is another essential question in glass science. Great efforts have been invested to develop a universal model to represent all glass structures. However, the concept of a universal structure model is incompatible with the fact that the vitreous state is in a thermodynamically metastable state because a specific structure can only arise in a thermodynamically stable state. To date, theories proposed on