Thermoelasticity of Fe2+-bearing bridgmanite

Shukla, Gaurav and Wu, Zhongqing and Hsu, Han and Floris, Andrea and Cococcioni, Matteo and Wentzcovitch, Renata M. (2015) Thermoelasticity of Fe2+-bearing bridgmanite. Geophysical Research Letters, 42 (6). pp. 1741-1749. ISSN 0094-8276

Full text not available from this repository.

Item Type:Article
Item Status:Live Archive

Abstract

We present local density approximation augmented by the Hubbard-type correction calculations of high-temperature elastic properties of bridgmanite with composition inline image for 0≤×≤0.125. Results of elastic moduli and acoustic velocities for the Mg end-member (x=0) agree very well with the latest high-pressure and high-temperature experimental measurements. In the iron-bearing system, we focus particularly on the change in thermoelastic parameters across the state change that occurs in ferrous iron above ∼30 GPa, often attributed to a high-spin (HS) to intermediate-spin (IS) crossover but explained by first-principles calculations as a lateral displacement of substitutional iron in the perovskite cage. We show that the measured effect of this change on the equation of state of this system can be explained by the lateral displacement of substitutional iron and not by the HS to IS crossover. The calculated elastic properties of inline image along an adiabatic mantle geotherm somewhat overestimate longitudinal velocities but produce densities and shear velocities quite consistent with the Preliminary Reference Earth Model data throughout most of the lower mantle

Keywords:High-pressure behaviour, Physical thermodynamics, Anelasticity, Equations of state, NotOAChecked
Subjects:F Physical Sciences > F690 Geology not elsewhere classified
Divisions:College of Science > School of Mathematics and Physics
Related URLs:
ID Code:22789
Deposited On:02 Jun 2016 09:34

Repository Staff Only: item control page