The spontaneous polarization and electrostatic potential in ferroelectric films with domain structures have been calculated based on phenomenological theory. The polarization is reduced at the film surface due to a depolarizing field. The domain width, free energy, and Curie temperature as functions of film thickness are obtained.

• Received 29 August 1994

DOI:https://doi.org/10.1103/PhysRevB.51.5311