Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1518802 | Journal of Physics and Chemistry of Solids | 2006 | 11 Pages |
Abstract
Non-equilibrium molecular dynamics simulations of the bulk rutile phase of TiO2 have been carried out in an intense external electromagnetic field with frequency in the microwave to far-infrared range. Simulations were performed in constant-volume ensembles with and without a thermostat coupled to the atomic degrees of freedom, at 298Â K and from 298Â K to well above the crystal melting temperature, respectively. Fields were applied along the a and c crystallographic directions. Both the Lekner and Ewald techniques were used to handle long-range electrostatics and the impact of different choices of Ewald parameters on the results has been evaluated. It was found that the ions respond rapidly to the field. The peaks and troughs in the Ti-Ti radial distribution functions were sharpened relative to the zero-field case at the instants of maximum electric field intensity, but little evidence of this was found for the Ti-O or O-O distributions. For pure Newtonian dynamics, the 500Â GHz field excited the vibrational modes to the greatest extent, raising the system temperature at the fastest rate. For temperatures above 2000-2500Â K, the crystal structure was found to melt. In the canonical ensemble, the 50Â GHz field led to the greatest enhancement of ionic translational mobility.
Related Topics
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Authors
Niall J. English, Dan C. Sorescu, J. Karl Johnson,