Abstract
Cubic zirconia exhibits a soft phonon mode which becomes dynamically unstable at low temperatures. Previous ab initio investigations into the temperature-induced stabilization of the soft mode treated it as an independent anharmonic oscillator. Calculations presented here, using the self-consistent ab initio lattice-dynamical method to evaluate the phonons at 2570 K, show that the soft mode should not be treated independently of other phonon modes. Phonon-phonon interactions stabilize the mode. Furthermore, the effective potential experienced by the mode takes on a quadratic form.
- Received 30 September 2008
DOI:https://doi.org/10.1103/PhysRevB.78.184304
©2008 American Physical Society