AI 中文总结
研究立方冰 Ic 能否从液态直接形成等问题，通过冷却介孔二氧化硅内水溶液在常压下获得原始立方冰 Ic，利用中子散射技术证明其可重复形成且为唯一稳定晶相，揭示该多晶型物在自然和合成过程中作用更重要。
AI 中文摘要
冷冻水的相图非常丰富：迄今为止，已鉴定出二十多种晶体多晶型物。在低压的“冰 I”族中，六方冰（Ih）是地球上的主要形式，而立方冰（Ic）则难以捉摸得多。关于立方冰 Ic 是否能直接从液态形成、其热力学稳定性和自然存在等基本问题仍未解决。在此我们表明，通过冷却限制在介孔二氧化硅内的水溶液，可在大气压下形成原始立方冰 Ic。主要利用中子散射技术，我们明确显示在这些条件下，立方冰 Ic 可重复形成且是水唯一热力学稳定的晶相。立方冰 Ic 可直接从液态获得且在常压下稳定这一发现，强烈表明这种多晶型物在自然和合成过程中所起的作用比之前认为的更为重要。
英文摘要
The phase diagram of frozen water is famously rich: to date, over twenty crystalline polymorphs have been identified. Of the low-pressure 'ice I' family, hexagonal (Ih) is the principal form on Earth, while cubic (Ic) is much more elusive. Fundamental questions remain open as to whether cubic ice Ic can form directly from the liquid state, its thermodynamic stability and natural occurrence. Here we show that pristine cubic ice Ic can be formed at atmospheric pressure simply by cooling an aqueous solution confined within mesoporous silica. Using primarily neutron scattering, we show unambiguously that under these conditions, cubic ice Ic forms reproducibly and is the only thermodynamically stable crystalline phase of water. The discovery that cubic ice Ic is directly accessible from the liquid state, and stable at atmospheric pressure, strongly suggests that this polymorph plays a much more significant role in natural and synthetic processes than previously thought.
