Dielectric anomalies in epitaxial films of relaxor ferroelectric (PbMg1/3Nb2/3O3)0.68-(PbTiO3)0.32 -: art. no. 224102

Dielectric anomalies observed in heterostructures of the epitaxial thin films of (PbMg1/3Nb2/3O3)(0.68-) (PbTiO3)(0.32), fabricated by in situ pulsed laser deposition on La0.5Sr0.5CoO3/MgO (100), and with metal top electrodes, were analyzed. The contribution of the film-electrode interfaces to the properties of the heterostructures was evaluated and the true properties of the films were reconstructed. Deviation from Curie-Weiss behavior, temperature evolution of the local order parameter, the Vogel-Fulcher relationship, and temperature evolution of the relaxation time spectrum were found in the films. The relaxer ferroelectric properties of the films were essentially similar to those of the single crystal. Also, it was shown that an apparent "relaxorlike" behavior in ferroelectric thin film heterostructures, evidenced only by a broad maximum and frequency dispersion of the dielectric permittivity, can be determined by the film-electrode interface rather than by the relaxer properties of the films.