文献类型：期刊文献

英文题名：New metallic ice phase under high pressure

作者：Huang, Yingying[1];Zhu, Liuyuan[1];Li, Hanlin[1];Fang, Haiping[1,2];Chen, Ruoyang[1];Sheng, Shiqi[1]

机构：[1]East China Univ Sci & Technol, Sch Phys, Shanghai 200237, Peoples R China;[2]Zhejiang Normal Univ, Dept Phys, Jinhua 321004, Peoples R China

年份：2024

卷号：26

期号：43

起止页码：27783

外文期刊名：PHYSICAL CHEMISTRY CHEMICAL PHYSICS

收录：;EI(收录号：20244617352836);WOS:【SCI-EXPANDED(收录号:WOS:001344214000001)】；

基金：Funding: This work was supported by the National Natural Science Foundation of China (12004109), the Natural Science Foundation of Shanghai, China (23JC1401400), Shanghai Pujiang Program (23PJ1401800), and the Fundamental Research Funds for the Central Universities of East China University of Science.

语种：英文

外文关键词：Calcium compounds - Cobalt compounds - Crystal atomic structure - Gallium phosphide - High pressure effects in solids - High pressure engineering - Lithium compounds - Mercury compounds - Metamorphic rocks - Potassium compounds - Sea ice - Silver oxides - Sodium compounds - Titanium dioxide - Transition metal oxides

摘要：Crystal materials can exhibit novel properties under high pressure, which are completely different from properties under ambient conditions. Water ice has an exceptionally rich phase diagram with at least 20 known crystalline ice phases from experiments, where the high-pressure ice X and ice XVIII behave as an ionic state and a superionic state, respectively. Thus, the ice structures stabilized under high pressure are very likely to possess other novel properties. Herein, we constructed a sequence of hypothetical high-pressure ices whose structures were generated according to the topological frameworks of common metal oxides. Based on density functional theory calculations, the pressure-induced phase transition sequence is in order that the known Ag2O-Pn (3) over barm structure (ice X) transformed into a previously undiscovered TiO2_brookite-Pbca structure at a pressure of 300 GPa, followed by a transition to a new NaO2-Pa3 structure at a pressure of 2120 GPa. Hitherto unreported NaO2-Pa3 ice with a cubic structure is in the ionic state, where the oxygen atoms in NaO2-Pa3 have a face-centered cubic (fcc) sublattice, and the coordination number of H atoms increases to 3. These two structures are dynamically stable according to phonon spectrum analysis and remain stable at temperature of 100 K based on ab initio molecular dynamics (AIMD) simulations. More importantly, the NaO2-Pa3 ice exhibits novel metallic properties with a closing band gap above a pressure of 2600 GPa, owing to the electron orbital coupling of oxygen atoms in close proximity induced by pressure.