Frustration on the Way to Crystallization in Glass
Some liquids do not crystallize below the melting point, but instead enter into a supercooled state and on cooling eventually become a glass at the glass-transition temperature. During this process, the liquid dynamics not only drastically slow down, but also become progressively more heterogeneous. The relationship between the kinetic slowing down and growing dynamic heterogeneity is a key problem of the liquid–glass transition. Here, we study this problem by using a liquid model, with a crystalline ground state, for which we can systematically control frustration against crystallization. We found that slow regions having a high degree of crystalline order emerge below the melting point, and their characteristic size and lifetime increase steeply on cooling. These crystalline regions lead to dynamic heterogeneity, suggesting a connection to the complex free-energy landscape and the resulting slow dynamics. These findings point towards an intrinsic link between the glass transition and crystallization.