题目：Computational support for a pyrolitic lower mantle containing ferric iron

报告人：王贤龙

时间：2015.06.24  下午2：30

地点：固体所新楼520会议室

摘要：The MgSiO₃ bridgmanite (MgBr) is believed to be the most abundant component in the Earth’s lower mantle, and MgBr contains a certain amount of impurities, such as Fe and Al. Therefore, to understand the lower mantle sufficiently, properties of Fe and Al-bearing MgBr under high-temperature and high-pressure conditions should be clarified clearly. Based on the first-principle method combined with the lattice dynamics method, we investigated equation of state (EoS), thermodynamic and thermoelastic properties of MgBr containing ~6.25 mol% impurities. The elastic wave velocities and densities of possible lower mantle aggregates are further calculated, and we find that taking PREM values as reference pyrolitic composition (~80 vol% MgBr and ~20 vol% Ferropericlase, Fe-bearing MgO) should be a reasonable lower mantle model. Fe in MgBr of pyrolite model should dominantly be ferric.