Fast crystalline ice formation at extremely low temperature through water/neon matrix sublimation
Fast crystalline ice formation at extremely low temperature through water/neon matrix sublimation
复制标题
通过水/氖基体升华在极低的温度下快速形成结晶冰
DOI：
10.1039/c7cp03315j
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发表时间：
2017
影响因子：
3.3
通讯作者：
Pirronello Valerio
中科院分区：
文献类型：
--
作者：
Hama Tetsuya;Ishizuka Shinnosuke;Yamazaki Tomoya;Kimura Yuki;Kouchi Akira;Watanabe Naoki;Sugimoto Toshiki;Pirronello Valerio
结晶冰的形成需要水分子有足够的移动的来找到并停留在化学上最稳定的位置。然而，在冷却时，扩散和重排在动力学上变得越来越困难。因此，在实验室中通过水蒸气冷凝生长的水冰通常被认为在低于100 K时处于亚稳的无定形形式。在这里，我们证明了在极低的温度下使用水/氖基质（1/1000，30 000单层）在6 K下制备，随后升温到11-12 K的结晶冰形成的可能性。 原位红外光谱揭示了分散的水分子的组装，在氖基质升华40-250秒期间形成结晶冰I。这一发现表明，在基质升华过程中，水分子的高流动性可以克服动力学障碍，即使在极低的温度下也能形成晶体。
Crystalline ice formation requires water molecules to be sufficiently mobile to find and settle on the thermodynamically most stable site. Upon cooling, however, diffusion and rearrangement become increasingly kinetically difficult. Water ice grown by the condensation of water vapor in laboratory is thus generally assumed to be in a metastable amorphous form below 100 K. Here, we demonstrate the possibility of crystalline ice formation at extremely low temperature using a water/neon matrix (1/1000, 30 000 monolayers) prepared at 6 K, which is subsequently warmed to 11–12 K. In situ infrared spectroscopy revealed the assembly of the dispersed water molecules, forming crystalline ice I during the sublimation of the neon matrix for 40–250 seconds. This finding indicates that the high mobility of the water molecules during matrix sublimation can overcome the kinetic barrier to form crystals even at extremely low temperature.