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论文类型： 期刊论文

发表时间： 2009-06-30

发表刊物： INTERNATIONAL JOURNAL OF MODERN PHYSICS B

收录刊物： SCIE

卷号： 23

期号： 16

页面范围： 3323-3329

ISSN号： 0217-9792

关键字： MgSiO3 perovskite; lower mantle; stability; computer simulation

摘要： Relative stability of different phases for MgSiO3 and (Mg-0:75, Fe-0.25) SiO3 within 0-110 GPa are investigated using first-principles method. For MgSiO3, the computed equation of state for orthorhombic phase of Pbnm space group agrees well with experimental results. The relative stability reduces from observed Pbnm orthorhombic phase to intermediated tetragonal P4mbm phase, and then to hypothetical cubic Pm (3) under barm phase. For (Mg-0:75, Fe-0.25) SiO3, the same sequence of relative phase stability is observed. Thus, the low-symmetric orthorhombic MgSiO3 should be favored in the lower mantle condition, while adding Fe into MgSiO3 will make it less stable at the same depth.