Properties of multilayer composite thin films based on Morphotropic Phase Boundary Pb(Mg1/3Nb2/3)O3-PbTiO3

Abstract

It has been reported that the ferroelectric and piezoelectric properties of Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMNT) thin films, with compositions close to the Morphotropic Phase Boundary (MPB), show much lower values than those of bulk ceramics with the same composition, which have been attributed to a reduction of the remnant polarization caused by the small size of the grains in the films. An alternative has been proposed to take full advantage of the excellent piezoelectric properties of polycrystalline PMNT in thin film form: a multilayer configuration that uses ferroelectric layers with large remnant polarization (Pr), in this case PbTiO3 (PT), to generate an internal electric bias within the PMNT layers and, thus, anchor an induced polarization on them and result in a consequent large piezoelectric behaviour. The detailed study of the properties of these multilayer composite (MLC) films reveals the complex correlations that arise in these heterostructures, which are key for the design of