Thermomechanical properties of non-stoichiometric gadolinium doped ceria by molecular dynamics simulations

Zhiwei Cui, Yi Sun, Jianmin Qu

Research output: Contribution to journalArticlepeer-review

4 Scopus citations

Abstract

Gadolinium doped ceria (GDC) will undergo chemical reduction reaction, yielding a discharge of the formal charged Ce4+ to Ce3+ under a low oxygen partial pressure. The effect of such chemical change on the mechanical response can be quantified by coefficient of compositional expansion (CCE) and elastic constants. In a recent paper, ab initio interionic pair potentials for GDC systems are derived based on the quantum mechanical calculation. Simulation results prove that the potential is reasonably good to be used for broad atomic simulations, except unphysical Cauchy relation. Consequently, in the current work, we propose an empirical three-body potential to modify the original ab initio interionic pair potential for GDC systems. The quality of the proposed potentials is verified by molecular dynamics simulations of CeO2 and solid solution GDC. We then use the potential to calculate the doped concentrations and temperature dependence of CCE and elastic constants. The CCE fits well with experiment data 0.06∼0.08. Meanwhile, the Young's modulus decreases with increasing vacancy concentration, while the variation of the Poisson's ratio is found to be negligible. In addition, both the elastic constants and the CCE are found to be insensitive to temperature.

Original languageEnglish
Pages (from-to)1359-1365
Number of pages7
JournalJournal of Computational and Theoretical Nanoscience
Volume10
Issue number6
DOIs
StatePublished - Jun 2013

Keywords

  • Ab Initio Potential
  • Elastic Constants
  • Empirical Three-Body Potential
  • Gadolinia-Doped Ceria
  • Molecular Dynamics Simulation

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