Institut für Physik, Johannes Gutenberg-Universität, 55099 Mainz, Germany.
J Phys Chem A. 2011 Apr 28;115(16):3713-9. doi: 10.1021/jp1060057. Epub 2010 Dec 20.
In recent years it has become widely accepted that a dynamical length scale ξ(α) plays an important role in supercooled liquids near the glass transition. We examine the implications of the interplay between the growing ξ(α) and the size of the crystal nucleus, ξ(M), which shrinks on cooling. We argue that at low temperatures where ξ(α) > ξ(M) a new crystallization mechanism emerges, enabling rapid development of a large scale web of sparsely connected crystallinity. Though we predict this web percolates the system at too low a temperature to be easily seen in the laboratory, there are noticeable residual effects near the glass transition that can account for several previously observed unexplained phenomena of deeply supercooled liquids including Fischer clusters and anomalous crystal growth near T(g).
近年来,人们普遍认为,在过冷液体接近玻璃转变时,动态长度标度 ξ(α) 起着重要作用。我们研究了不断增长的 ξ(α) 和晶体核大小 ξ(M) 之间的相互作用的含义,后者在冷却时会收缩。我们认为,在 ξ(α) > ξ(M) 的低温下,出现了一种新的结晶机制,能够快速形成一个稀疏连接结晶度的大尺度网络。虽然我们预测这个网络在太低的温度下会使系统渗透,以至于在实验室中不容易看到,但在玻璃转变附近有明显的残留效应,可以解释几个以前观察到的过冷液体的未解释现象,包括 Fischer 团簇和 T(g) 附近的异常晶体生长。