Wiley-Blackwell;Washington: American Geophysical Union (AGU)
摘要:
摘要： AbstractWe present local density approximation augmented by the Hubbard‐type correction calculations of high‐temperature elastic properties of bridgmanite with composition <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="graphic/grl52689-math-0001.png" xlink:title="urn:x-wiley:grl:media:grl52689:grl52689-math-0001"/> 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 <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="graphic/grl52689-math-0002.png" xlink:title="urn:x-wiley:grl:media:grl52689:grl52689-math-0002"/> 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. 出版者： Washington: American Geophysical Union (AGU) 出版日期： 2015-03-28 出處： Geophysical Research Letters, 2015-03, Vol.42 (6), p.1741-1749 資源來源： Wiley Online Library - AutoHoldings Journals 版權： 2015. American Geophysical Union. All Rights Reserved. 版權： Copyright Blackwell Publishing Ltd. Mar 2015 識別號： ISSN: 0094-8276 識別號： EISSN: 1944-8007 識別號： DOI: 10.1002/2014gl062888
