Ab initio elasticity and thermal equation of state of MgSiO3 perovskite

被引：132

作者：

Oganov, AR ^{[1
]}

Brodholt, JP ^{[1
]}

Price, GD ^{[1
]}

机构：

[1] UCL, Dept Geol Sci, London WC1E 6BT, England

来源：

EARTH AND PLANETARY SCIENCE LETTERS | 2001年 / 184卷 / 3-4期

关键词：

perovskite; lower mantle; equations of state; thermal expansion; elastic constants; Gruneisen parameters; thermoelastic properties;

D O I：

10.1016/S0012-821X(00)00363-0

中图分类号：

P3 [地球物理学]; P59 [地球化学];

学科分类号：

0708 ; 070902 ;

摘要：

We have used high-temperature ab initio molecular dynamic simulations to study the equation of state of orthorhombic MgSiO(3) perovskite under lower mantle pressure-temperature conditions. We have determined the Gruneisen parameter, gamma, as a function of volume. Our state-of-the-art simulations, accurate to within 10%, resolve the long-standing controversy on thermal expansion (a) and Gruneisen parameter of MgSiO(3) perovskite. Under ambient conditions we find the values for alpha and gamma of 1.86 x 10(-5) K(-1) and 1.51, respectively, in excellent agreement with the latest experimental studies. Calculated elastic constants and the static equation of state at 0 K agree well with previous simulations. We have found no evidence for the high-temperature phase transitions of orthorhombic MgSiO(3) perovskite to cubic or tetragonal phases at mantle temperatures. (C) 2001 Elsevier Science B.V. All rights reserved.

引用

页码：555 / 560

页数：6

共 25 条

[1] HEAT-CAPACITY OF MGSIO3 PEROVSKITE [J].