Book contents
- Frontmatter
- Contents
- Preface
- List of Contributors
- Part I Introduction
- Part II Advances in Theoretical and Experimental Techniques
- Part III New Findings in Oxides and Silicates
- Chapter 3.1 Search for a Connection Among Bond Strength, Bond Length, and Electron-Density Distributions
- Chapter 3.2 MgO – The Simplest Oxide
- Chapter 3.3 First-Principles Theoretical Study of the High-Pressure Phases of MnO and FeO: Normal and Inverse NiAs Structures
- Chapter 3.4 Computer-Simulation Approach to the Thermoelastic, Transport, and Melting Properties of Lower-Mantle Phases
- Part IV Transformations in Silica
- Part V Novel Structures and Materials
- Part VI Melts and Crystal–Melt Interactions
- Subject Index
- Materials Formula Index
- Index of Contributors
Chapter 3.4 - Computer-Simulation Approach to the Thermoelastic, Transport, and Melting Properties of Lower-Mantle Phases
Published online by Cambridge University Press: 05 November 2011
- Frontmatter
- Contents
- Preface
- List of Contributors
- Part I Introduction
- Part II Advances in Theoretical and Experimental Techniques
- Part III New Findings in Oxides and Silicates
- Chapter 3.1 Search for a Connection Among Bond Strength, Bond Length, and Electron-Density Distributions
- Chapter 3.2 MgO – The Simplest Oxide
- Chapter 3.3 First-Principles Theoretical Study of the High-Pressure Phases of MnO and FeO: Normal and Inverse NiAs Structures
- Chapter 3.4 Computer-Simulation Approach to the Thermoelastic, Transport, and Melting Properties of Lower-Mantle Phases
- Part IV Transformations in Silica
- Part V Novel Structures and Materials
- Part VI Melts and Crystal–Melt Interactions
- Subject Index
- Materials Formula Index
- Index of Contributors
Summary
This chapter is in honour of Y. Matsui and his significant contributions to mineral physics. We review some of our recent computer-simulation studies of the lower-mantle phases of MgSiO3 perovskite and MgO with respect to the predicted thermoelastic properties and diffusion behaviour. The geophysical significance of these calculations is outlined. Then we outline the theory behind the lattice dynamics of perfect and defective systems and molecular dynamics techniques. We also discuss the atomistic diffusion theories in relation to our computer simulation approaches. Finally, we present the results of our studies.
Introduction
We discuss work that we have carried out on geophysically important phenomena, namely (1) the equations of state of MgSiO3 perovskite and (2) diffusion in MgO (see Fig. 3.4.1).
To model the composition of the lower mantle it is necessary to obtain accurate thermoelastic parameters that are used in equations of state of the component minerals. Experiments at these extreme pressure and temperature conditions are difficult and can lead to large uncertainties in some of the thermoelastic constants. Recent reports reveal that there are discrepancies in the data obtained by various experimental studies of silicate perovskite, the most abundant mineral in the Earth. Both the x-ray-diffraction diamond-anvil-cell measurements of Mao et al. [1] and the multianvil high-pressure experiments of Wang et al. [2] are in agreement in their measurement of compressibility and the associated Birch–Murnaghan equation of state, but they differ for thevalues of the Griineisen and the Anderson–Griineisen parameters inferred. Moreover, the thermodynamic analyses of Anderson and Masuda [3] and the spectroscopic measurements of Chopelas [4] have yielded thermoelastic data that are in good agreement with the measurements of Wang et al.
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- Physics Meets MineralogyCondensed Matter Physics in the Geosciences, pp. 143 - 170Publisher: Cambridge University PressPrint publication year: 2000