Unveiling the medium-range order in glass models and its role in glass formation

Abstract

The correlation between structure and glass formability in glassy systems is a long-standing puzzle. To solve this puzzle, many descriptors based on the short-range order (SRO) have been proposed. Here we show that the SRO, however, offers little help in explaining the glass formability and stability; instead it is the formation of medium-range order that stabilizes the glass against crystallization by suppressing the atomic rearrangement and compositional change. Our results provide a perspective for understanding the correlation between structure and stability in glasses.

Concerning the formation of chains of particles in the Kob-Andersen (4:1) and Wahnstr{ö}m (1:1) model liquids on coolind and supercooling

“…Earlier computer simulation studies were usually focused on considerations of local atomic environments of individual particles, essentially, limited by the nearest neighbor shells [1,2,[10][11][12]. In more recent studies, it has been realized that interactions with the second and more distant neighbors (mediumrange order) are also important for understanding the liquids' dynamics and, in particular, the relevant relaxation timescales [3,9,[12][13][14][15][16][17][18][19][20][21][22][23][24].…”