Formation of solid SiO2He compound at high pressure and high temperature

被引：10

作者：

Ding, Shicong ^{[1
]}

Zhang, Pan ^{[1
]}

Yang, Kang ^{[1
]}

Liu, Cailong ^{[2
]}

Hao, Jian ^{[1
]}

Cui, Wenwen ^{[1
]}

Shi, Jingming ^{[1
]}

Li, Yinwei ^{[1
,2
]}

机构：

[1] Jiangsu Normal Univ, Sch Phys & Elect Engn, Lab Quantum Funct Mat Design & Applicat, Xuzhou 221116, Jiangsu, Peoples R China

[2] Liaocheng Univ, Sch Phys Sci Informat Technol, Shandong Key Lab Opt Commun Sci & Technol, Liaocheng 252059, Shandong, Peoples R China

来源：

PHYSICAL REVIEW B | 2022年 / 106卷 / 02期

关键词：

GENERALIZED GRADIENT APPROXIMATION; TOTAL-ENERGY CALCULATIONS; CRYSTAL-STRUCTURE; GAS GIANTS; HELIUM; PHASE; PREDICTION; STISHOVITE; TRANSFORMATIONS; CRISTOBALITE;

D O I：

10.1103/PhysRevB.106.024102

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

Silica, a main mineral inside the Earth and super-Earth, is generally assumed to be resistant to react with noble gas elements at ambient conditions. Here, combining crystal structural prediction and first-principles calculation, we predict a SiO2He compound that becomes stable at high pressure. Each Si (He) atom in the SiO2He is bonded with seven O atoms and two He (Si) atoms, forming a Si-centered SiO7He2 (He-centered HeO7Si2) polyhedron. Further calculations indicate that the SiO2He compound remains solid over a wide range of pressures exceeding 607 GPa and temperatures of 0-9000 K, covering the extreme conditions of the core-mantle boundary in super-Earth exoplanets or even in the ice giants of our solar system. Our results may provide theoretical guidance for the discovery of other silicides at high pressures, which promote the exploration of materials at planetary core-mantle boundaries, and enable planetary models to be refined as well.

引用

页数：6

共 67 条

[1] THE QUARTZ COESITE STISHOVITE TRANSFORMATIONS - NEW CALORIMETRIC MEASUREMENTS AND CALCULATION OF PHASE-DIAGRAMS [J].