Elastic anisotropy of FeSiO3 end‐members of the perovskite and post‐perovskite phases
Elastic anisotropy of FeSiO3 end‐members of the perovskite and post‐perovskite phases
复制标题
钙钛矿相和后钙钛矿相 FeSiO3 端元的弹性各向异性
DOI：
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
G. Price
中科院分区：
文献类型：
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作者：
S. Stackhouse;J. Brodholt;G. Price
纯端元 FeSiO3 的钙钛矿和后钙钛矿多晶型物的非热弹性常数是从头算计算得到的。我们预测，将 10 摩尔% FeSiO3 与 4 摩尔% Al2O3 结合到 MgSiO3 中，可使钙钛矿到后钙钛矿相变压力降低 5 GPa。由于铁和氧化铝的掺入，后钙钛矿相的地震特性发生微小变化，这与下地幔的观测结果是一致的。富含 50% 或更多铁的 MgSiO3 后钙钛矿可能是地幔底部超低速区的原因。
The athermal elastic constants of the perovskite and post‐perovskite polymorphs of pure end‐member FeSiO3 were calculated from ab initio calculations. We predict that incorporating ten mole percent FeSiO3 together with four mole percent Al2O3 into MgSiO3 reduces the perovskite to post‐perovskite phase transition pressure by 5 GPa. Small changes in the seismic properties of the post‐perovskite phase due to the incorporation of iron and alumina are compatible with observations for the lower mantle. MgSiO3 post‐perovskite enriched in fifty percent or more iron may be responsible for ultra‐low velocity zones at the base of the mantle.