Free energy and molecular dynamics calculations for the cubictetragonal phase transition in zirconia
Abstract
The hightemperature cubictetragonal phase transition of pure stoichiometric zirconia is studied by molecular dynamics (MD) simulations and within the framework of the Landau theory of phase transformations. The interatomic forces are calculated using an empirical, selfconsistent, orthogonal tightbinding model, which includes atomic polarizabilities up to the quadrupolar level. A first set of standard MD calculations shows that, on increasing temperature, one particular vibrational frequency softens. The temperature evolution of the freeenergy surfaces around the phase transition is then studied with a second set of calculations. These combine the thermodynamic integration technique with constrained MD simulations. The results seem to support the thesis of a secondorder phase transition but with unusual, very anharmonic behavior above the transition temperature.
 Publication:

Physical Review B
 Pub Date:
 March 2001
 DOI:
 10.1103/PhysRevB.63.094101
 arXiv:
 arXiv:condmat/0102526
 Bibcode:
 2001PhRvB..63i4101F
 Keywords:

 64.60.i;
 81.30.t;
 71.15.Ap;
 General studies of phase transitions;
 Phase diagrams and microstructures developed by solidification and solidsolid phase transformations;
 Basis sets and related methodology;
 Condensed Matter  Materials Science
 EPrint:
 Phys. Rev. B {\bf 63}, 094101 (2001)