Surface premelting and melting of colloidal glasses

Abstract

The nature of liquid-to-glass transition is a major puzzle in science. A similar challenge exists in glass-to-liquid transition, i.e., glass melting, especially for the poorly investigated surface effects. Here, we assemble colloidal glasses by vapor deposition and melt them by tuning particle attractions. The structural and dynamic parameters saturate at different depths, which define a surface liquid layer and an intermediate glassy layer. The power-law growth of both layers and melting front behaviors at different heating rates are similar to crystal premelting and melting, suggesting that premelting and melting can be generalized to amorphous solids. The measured single-particle kinetics reveal various features and confirm theoretical predictions for glass surface layer.

Supercriticality, Glassy Dynamics, and the New Insight into Melting/Freezing Discontinuous Transition in Linseed Oil

“…therein. They can be as follows [62,[75][76][77][78][79][80][81][82][83][84][85][86][87][88][89][90]: (i) premelting effects are 'weak' and rangelimited, (ii) they are detected only for some systems, (iii) they are detected for selected physical properties, (iv) there are no reports on their parameterization, except the very recent ref. [72], and (v) no solid-state pretransitional effects for freezing, i.e.…”

“…Despite the apparent limitations and problems, premelting effects are commonly considered the gateway for explaining the nature of melting/freezing discontinuous phase transitions [62,72,[75][76][77][78][79][80][81][82][83][84][85][86][87][88][89][90]. This cognitive situation is qualitatively different from continuous phase transitions: understanding their origins is one of the greatest universalistic successes of 20th-century physics, as concluded in Critical Phenomena Physics [33].…”

“…For melting/freezing discontinuous transitions, such pretransitional effects are (almost) absent, except for the puzzling premelting effects in the solid state [62,[75][76][77][78][79][80][81][82][83][84][85][86][87][88][89][90]. In linseed oil, both premelting and post-freezing effects exist, and the latter are even stronger and longer ranged.…”