Simulating Phase Transitions and Thermoelasticity of Mantle Minerals

Ab initio theory of phase transitions and thermoelasticity of minerals

Accurate quantum-mechanical simulations have significantly extended the current picture of the Earth and hold a great promise for the future of the Earth and planetary sciences. Studies of phase transitions, equations of state, elasticity and thermoelastic properties of the Earth-forming minerals are essential to geophysics. This chapter gives a basic background of the physics of the deep Earth...

First Principles Quasiharmonic Thermoelasticity of Mantle Minerals

Thermodynamic (Anderson 2005) and elastic properties (Musgrave 1970) of minerals provide the fundamental information needed to analyze seismic observations and to model Earth’s dynamic state. The connection between pressure, temperature, chemical composition, and mineralogy that produce seismic velocity gradients, heterogeneities, and discontinuities, can be established with knowledge of thermo...

Theory of displacive phase transitions in minerals

A lattice-dynamical treatment of displacive phase transitions leads naturally to the softmode model, in which the phase-transition mechanism involves a phonon frequency that falls to zero at the transition temperature. The basic ideas of this approach are reviewed in relation to displacive phase transitions in silicates. A simple free-energy model is used to demonstrate that Landau theory gives...

Effects of Phase Transitions on Mantle Convection

Mantle convection--the creeping flow of solid mantle rock driven by buoyancy forces predominantly arising from thermal expansion--is the accepted paradigm for explaining the internal geological activity of the Earth. Its theoretical understanding is largely based on the simple concept of RayleighB6nard convection. Here, one assumes a fluid layer of infinite lateral extent and constant material ...

Multi-Mbar Phase Transitions in Minerals