A computer simulation study of the effect of pressure on Mg diffusion in forsterite
MetadataShow full item record
Computer simulation techniques were used to investigate the effect of pressure on magnesium diffusionin forsterite between 0 and 10 GPa. We studied the diffusion path along the c crystallographic axis (we always refer to the Pbnm system) via a vacancy mechanism. Using a Mott-Littleton approach withinthe code GULP, we were able to precisely map the diffusion path of a Mg vacancy and we found theactivation energy, E = 3.97 eV at 0 GPa (with Ef = 3.35 eV for the formation energy and Em = 0.62 eV for the migration) and E = 4.46 eV at 10 GPa (Ef = 3.81 eV and Em = 0.65 eV). Preliminary results using the supercell technique gave the same saddle point coordinates and energies. This saddle point of the Mg vacancy diffusion found with GULP was then introduced in an ab initio code, confirming the values of the migration energy both at 0 and 10 GPa. We were therefore able to estimate the activation volume (V) to be around 5 cm3/mol and d(V)/dP = 0. The effect of pressure applies mostly on defect formation and little on migration.
Copyright © 2009 Elsevier B.V. All rights reserved
Showing items related by title, author, creator and subject.
Zhong, Yongmin; Shirinzadeh, B.; Alici, G.; Smith, J. (2006)In this paper, a new methodology is presented to simulatedeformation of soft objects by the reaction-diffusion analogy. Thepotential energy generated by an external force as a result of adeformation is propagated among ...
Cryogenic Helium Adsorbed in Zeolite Rho: Inside Localization Controlled Self-Diffusion of Confined Quantum ParticlesKowalczyk, Piotr; Gauden, P.; Terzyk, A.; Furmaniak, S.; Kaneko, K. (2011)Applying Feynman’s treatment of quantum mechanics at finite temperatures via path integrals and the numerical analytic continuation method developed recently (Kowalczyk, P.; Gauden, P. A.; Terzyk, A. P.; Furmaniak, ...
Reactive force field simulation of proton diffusion in BaZrO3 using an empirical valence bond approachRaiteri, Paolo; Gale, Julian; Bussi, G. (2011)A new reactive force field to describe proton diffusion within the solid-oxide fuel cell material BaZrO3 has been derived. Using a quantum mechanical potential energy surface, the parameters of an interatomic potential ...