(342t) Si and C Models as the Basis for Regression-Driven Development of the Interface Force Field
AIChE Annual Meeting
2021
2021 Annual Meeting
Computational Molecular Science and Engineering Forum
CoMSEF Poster Session
Tuesday, November 9, 2021 - 3:30pm to 5:00pm
Via an ancillary electron method, we constructed a silicon (Si) model which reproduces a density of 2.312 g/cm3 at 298 K, compared to 2.329 g/cm3 as experimentally measured.2 Our model is representative of experimentally observed Si melting temperature near 1687 K, largely owing to accurate description of surface energy which we demonstrate through the calculation of the Si(111) surface energy within 5% error of experimental estimates.3 A similar model was constructed for carbon. Si and C were assembled to simulate the SiC layer that results from heterogeneous nucleation between C and molten Si during melt infiltration experiments. In the solid-state diffusion-controlled regime of the reaction occurring at the interface, the diffusivity of C through the initial nucleation layer of SiC governs further layer growth. We calculated the diffusivity of C through SiC layers of various thickness in order to investigate the effect of the time-dependent permeability on layer growth.
Where diffusivity is critical to reaction rate, as in the SiC system, a model that captures nanoscale system dynamics is necessary for micron-scale material simulation. Through accurate description of diffusivity in SiC, our Si and C ancillary electron models advance the capabilities of Interface Force Field for ceramic materials.
References:
(1) Heinz, H., Lin, T.-J., Kishore Mishra, R., & Emami, F. S. (2013). Thermodynamically Consistent Force Fields for the Assembly of Inorganic, Organic, and Biological Nanostructures: The INTERFACE Force Field. Langmuir, 29(6), 1754â1765. https://doi.org/10.1021/la3038846
(2) Assael, M. J., Armyra, I. J., Brillo, J., Stankus, S. V., Wu, J., & Wakeham, W. A. (2012). Reference Data for the Density and Viscosity of Liquid Cadmium, Cobalt, Gallium, Indium, Mercury, Silicon, Thallium, and Zinc. Journal of Physical and Chemical Reference Data, 41(3), 033101. https://doi.org/10.1063/1.4729873
(3) Tyson, W. R., & Miller, W. A. (1977). Surface free energies of solid metals: Estimation from liquid surface tension measurements. Surface Science, 62(1), 267â276. https://doi.org/10.1016/0039-6028(77)90442-3