Topologically disordered mesophase at the topmost surface layer of crystalline ice between 120 and 200 K
Topologically disordered mesophase at the topmost surface layer of crystalline ice between 120 and 200 K
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DOI：
10.1103/physrevb.99.121402
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发表时间：
2019-03
影响因子：
3.7
通讯作者：
T. Sugimoto;Yuji Otsuki;T. Ishiyama;A. Morita;Kazuya Watanabe;Y. Matsumoto
中科院分区：
文献类型：
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作者：
T. Sugimoto;Yuji Otsuki;T. Ishiyama;A. Morita;Kazuya Watanabe;Y. Matsumoto
冰表面在融化时的结构和动力学在地球和宇宙的各种现象中都是至关重要的，因为冰表面不协调的水分子具有独特的物理和化学性质，与整体上完全协调的分子不同。利用表面特异性和频率产生光谱和分子动力学模拟，我们证明了在晶体冰的最表层出现了拓扑无序的氢键网络，其温度远低于传统认为的预熔温度。在120 ~ 200 K之间，冰表面通过拓扑无序的中间相经历了从低温固相到高温准液相的一系列结构转变。因为地球大气温度的下限是在中层顶附近，所以地球上最表层的结晶冰不太可能是完全有序的固体。
The structure and dynamics of an ice surface upon melting are of paramount importance in a variety of phenomena on earth and in the universe because undercoordinated water molecules at an ice surface have peculiar physical and chemical properties distinct from fully coordinated molecules in bulk. Using surface-specific sum-frequency generation spectroscopy and molecular dynamics simulations, we demonstrate that a topologically disordered hydrogen-bond network emerges at the topmost surface layer of crystalline ice Ih(0001) atthat is much lower than the conventionally believed premelting temperature of. The ice surface undergoes a cascade of structural transitions from a low-temperature solid phase to high-temperature quasiliquid phase via the topologically disordered mesophase between 120 and 200 K. Because the lower limit of temperature of the earth's atmosphere isaround the mesopause, the topmost surface layers of crystalline ice on earth are unlikely to be the perfectly ordered solid.