Futera Zdenek, Tse John S, English Niall J
Faculty of Science, University of South Bohemia, Branisovska 1760, Ceske Budejovice 370 05, Czech Republic.
Department of Physics and Engineering Physics, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2, Canada.
Sci Adv. 2020 May 22;6(21):eaaz2915. doi: 10.1126/sciadv.aaz2915. eCollection 2020 May.
In a superionic (SI) ice phase, oxygen atoms remain crystallographically ordered while protons become fully diffusive as a result of intramolecular dissociation. Ice VII's importance as a potential candidate for a SI ice phase has been conjectured from anomalous proton diffusivity data. Theoretical studies indicate possible SI prevalence in large-planet mantles (e.g., Uranus and Neptune) and exoplanets. Here, we realize sustainable SI behavior in ice VII by means of externally applied electric fields, using state-of-the-art nonequilibrium ab initio molecular dynamics to witness at first hand the protons' fluid dance through a dipole-ordered ice VII lattice. We point out the possibility of SI ice VII on Venus, in its strong permanent electric field.
在超离子（SI）冰相中，氧原子保持晶体学有序，而质子由于分子内解离而变得完全扩散。根据反常的质子扩散率数据推测，冰VII作为SI冰相的潜在候选物具有重要意义。理论研究表明，在大行星（如天王星和海王星）的地幔以及系外行星中可能普遍存在SI冰相。在此，我们通过外部施加电场在冰VII中实现了可持续的SI行为，利用最先进的非平衡从头算分子动力学直接见证质子在偶极有序的冰VII晶格中的流动。我们指出，在金星强大的永久电场中可能存在SI冰VII。
