Polarization reversal in a perovskite ferroelectric by molecular-dynamics simulation

SEPLIARSKY, M.; PHILLPOT, S.R.; STREIFFER, S.K.; STACHIOTTI, M.G.; MIGONI, R.L.

APPLIED PHYSICS LETTERS

AMER INST PHYSICS

Año: 2001 vol. 79 p. 4417 - 4419

0003-6951

We characterize the microscopic processes that take place during polarization reversal in the tetragonal phase of a monodomain order-disorder perovskite ferroelectric using molecular-dynamics simulation. Microscopically the polarization of each unit cell reorients from an [001] orientation to an [001̄] orientation through intermediate states with polarization parallel to [011] and [011̄]. For low electric field and low temperature, chains of polarization reverse in a spatially coherent manner, resulting in macroscopic intermediate states with orthorhombic symmetry. At high electric field and high temperature the process is completely incoherent and there is no well-defined macroscopic intermediate state. © 2001 American Institute of Physics.