Influence of polarizability on metal oxide properties studied by molecular dynamics simulations

Autor: Beck, Philipp, Brommer, Peter, Roth, Johannes, Trebin, Hans-Rainer
Rok vydání: 2012
Předmět:
Zdroj: J. Phys.: Condens. Matter 24 (2012) 485401
Druh dokumentu: Working Paper
DOI: 10.1088/0953-8984/24/48/485401
Popis: We have studied the dependence of metal oxide properties in molecular dynamics (MD) simulations on the polarizability of oxygen ions. We present studies of both liquid and crystalline structures of silica (SiO2), magnesia (MgO) and alumina (Al2O3). For each of the three oxides, two separately optimized sets of force fields were used: (i) Long-range Coulomb interactions between oxide and metal ions combined with a short-range pair potential. (ii) Extension of force field (i) by adding polarizability to the oxygen ions. We show that while an effective potential of type (i) without polarizable oxygen ions can describe radial distributions and lattice constants reasonably well, potentials of type (ii) are required to obtain correct values for bond angles and the equation of state. The importance of polarizability for metal oxide properties decreases with increasing temperature.
Comment: 8 pages, 7 figures
Databáze: arXiv