Liquid-like atoms in dense-packed solid glasses

• Published in: Nature materials 2022-11, Vol.21 (11), p.1240-1245
• Main Authors: Chang, C., Zhang, H. P., Zhao, R., Li, F. C., Luo, P., Li, M. Z., Bai, H. Y.
• Format: Article
• Language: English
• Subjects: 639/301/1023/218; 639/301/119/1002; Amorphous materials; Biomaterials; Chemistry and Materials Science; Condensed Matter Physics; Diffusion rate; Dynamic structural analysis; High temperature; Inheritances; Letter; Liquids; Low temperature; Materials Science; Metallic glasses; Nanotechnology; Optical and Electronic Materials; Physics; Room temperature; Temperature; Viscosity
• ISSN: 1476-1122; 1476-4660
• DOI: 10.1038/s41563-022-01327-w

Revealing the microscopic structural and dynamic pictures of glasses is a long-standing challenge for scientists 1 , 2 . Extensive studies on the structure and relaxation dynamics of glasses have constructed the current classical picture 3 – 5 : glasses consist of some ‘soft zones’ of loosely bound atoms embedded in a tightly bound atomic matrix. Recent experiments have found an additional fast process in the relaxation spectra 6 – 9 , but the underlying physics of this process remains unclear. Here, combining extensive dynamic experiments and computer simulations, we reveal that this fast relaxation is associated with string-like diffusion of liquid-like atoms, which are inherited from the high-temperature liquids. Even at room temperature, some atoms in dense-packed metallic glasses can diffuse just as easily as they would in liquid states, with an experimentally determined viscosity as low as 10 7  Pa·s. This finding extends our current microscopic picture of glass solids and might help establish the dynamics–property relationship of glasses 4 . The existence of fast dynamics in glass solids at low temperatures is attributed to liquid-like atoms that are inherited from high-temperature liquids and exhibit behaviour similar to that of atoms in liquid states.