Effects of synthesis conditions on electrical properties of chemical solution deposition-derived Pb(Mg1/3Nb2/3)O3-PbTiO3 thin films

Relaxor ferroelectrics Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) have attracted considerable attention because of their excellent electrical properties, which include high dielectricity and piezoelectricity. Their thin films are promising for use as super capacitors and piezoelectric actuators. However, the reported electrical properties of PMN-PT thin films, such as dielectric and piezoelectric properties, are markedly lower than those of bulk ceramics and single-crystals. This study investigated the effects of synthesis conditions such as annealing temperatures, excess lead amounts, and the molecular design of the precursor solution on the electrical properties of the Chemical Solution Deposition (CSD)-derived PMN-PT thin films to deposit single-phase perovskite PMN-PT thin films with superior electrical properties on a Si substrate at lower temperatures. Results of studies demonstrated effectively that suitable processing is necessary to elicit the enhanced electrical properties of PMN-PT thin films, such as introduction of suitable seeding layers and optimization of synthesis conditions. Results show that CSD-derived polycrystalline 0.65PMN-0.35PT thin films with preferred orientation exhibited a higher dielectric constant over 4000 (1 kHz, at room temperature) and higher remanent polarization of Pr = 27.7 μC/cm2 (1000 kV/cm, at room temperature) as well as a higher electrostrictive constant of d33 about 200 pm/V. Further investigation and development are expected to improve these electrical properties of the PMN-PT thin films by stress engineering or residual stress.