DOI: 10.1002/2016GL069332
论文题名: Thermoelasticity of Fe3+- and Al-bearing bridgmanite: Effects of iron spin crossover
作者: Shukla G. ; Cococcioni M. ; Wentzcovitch R.M.
刊名: Geophysical Research Letters
ISSN: 0094-8981
EISSN: 1944-8712
出版年: 2016
卷: 43, 期: 11 起始页码: 5661
结束页码: 5670
语种: 英语
英文关键词: elastic anomalies
; lower mantle
; thermoelasticty
Scopus关键词: Calculations
; Elasticity
; Silicon
; Thermoelasticity
; Coupled substitution
; Elastic anomalies
; Elastic properties
; Lower mantle
; Pressure and temperature
; Thermoelastic properties
; Thermoelasticty
; Transition regions
; Aluminum
英文摘要: We report ab initio (LDA + Usc) calculations of thermoelastic properties of ferric iron (Fe3+)- and aluminum (Al)-bearing bridgmanite (MgSiO3 perovskite), the main Earth forming phase, at relevant pressure and temperature conditions and compositions. Three coupled substitutions, namely, [Al]Mg-[Al]Si, [Fe3+]Mg-[Fe3+]Si, and [Fe3+]Mg-[Al]Si have been investigated. Aggregate elastic moduli and sound velocities are successfully compared with limited experimental data available. In the case of [Fe3+]Mg-[Fe3+]Si substitution, the high-spin (S = 5/2) to low-spin (S = 1/2) crossover in [Fe3+]Si induces a volume collapse and elastic anomalies across the transition region. However, the associated anomalies should disappear in the presence of aluminum in the most favorable substitution, i.e., [Fe3+]Mg-[Al]Si. Calculated elastic properties along a lower mantle model geotherm suggest that the elastic behavior of bridgmanite with simultaneous substitution of Fe2O3 and Al2O3 in equal proportions or with Al2O3 in excess should be similar to that of (Mg,Fe2+)SiO3 bridgmanite. However, excess of Fe2O3 should produce elastic anomalies in the crossover pressure region. ©2016. American Geophysical Union. All Rights Reserved. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84973160221&doi=10.1002%2f2016GL069332&partnerID=40&md5=14c985acb9f5dcb5e02ce4248f8c8b74
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/9944
Appears in Collections: 科学计划与规划 气候变化与战略
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作者单位: School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, United States
Recommended Citation:
Shukla G.,Cococcioni M.,Wentzcovitch R.M.. Thermoelasticity of Fe3+- and Al-bearing bridgmanite: Effects of iron spin crossover[J]. Geophysical Research Letters,2016-01-01,43(11).