TY - JOUR
T1 - Thermomechanical properties of non-stoichiometric gadolinium doped ceria by molecular dynamics simulations
AU - Cui, Zhiwei
AU - Sun, Yi
AU - Qu, Jianmin
PY - 2013/6
Y1 - 2013/6
N2 - 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.
AB - 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.
KW - Ab Initio Potential
KW - Elastic Constants
KW - Empirical Three-Body Potential
KW - Gadolinia-Doped Ceria
KW - Molecular Dynamics Simulation
UR - http://www.scopus.com/inward/record.url?scp=84879633130&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84879633130&partnerID=8YFLogxK
U2 - 10.1166/jctn.2013.2856
DO - 10.1166/jctn.2013.2856
M3 - Article
AN - SCOPUS:84879633130
SN - 1546-1955
VL - 10
SP - 1359
EP - 1365
JO - Journal of Computational and Theoretical Nanoscience
JF - Journal of Computational and Theoretical Nanoscience
IS - 6
ER -