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Mineral Physics Institute
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| Aaron Palke
This summer's research with Dr. Phillip Allen involves computational modeling of the thermodynamic properties of periclase, or MgO, at high temperatures typical of the deep mantle. Understanding the behavior of periclase under the pressure and temperature conditions of the mantle is important for understanding the physical properties of the mantle at large. However, it is impossible, or nearly so, to conduct experiments on periclase at such high temperatures. So we will turn to computational methods to attempt to determine the thermal conductivity of periclase at high temperatures. Periclase was chosen for this project because it is the dominant oxide in the mantle and its relatively simple atomic structure lends itself very well to a simple computational model. The model we will attempt to develop is inspired by a computational model developed by Fermi, Pasta, and Ulam in which they considered the transfer of energy between different modes of vibrational motion in a simple, one-dimensional string of particles modeled by simple Newtonian forces. In this problem they considered the forces between the different particles to have a non-linear dependence on the distance between particles. The consequence is that when the ‘string' was modeled with an amount of energy in a certain vibrational mode the energy had a tendency to move between different vibrational modes as the computational experiment progressed. By recreating this experiment for a model of the MgO crystal lattice we hope to observe the movement of energy between different vibrational modes and apply the information on this energy movement to the problem of the thermal conductivity of periclase at deep mantle conditions. |
Modified June 20, 2007
