Synthesis and properties of BiScO3-PbTiO3 powders and thin films using metal-organic precursor solutions

Abstract

The BiScO3–PbTiO3 binary system is known to have a morphotropic phase boundary (MPB) and a higher Curie temperature than Pb(Zr,Ti)O3 and to exhibit excellent dielectric and ferroelectric properties. Perovskite BiScO3–PbTiO3 powders and thin films were synthesized via a chemical process using metal-organic precursor solutions. Homogeneous and stable precursor solutions, perovskite BiScO3–PbTiO3 single-phase powders and thin films on Pt/TiOx/SiO2/Si substrates were successfully prepared by optimizing the processing conditions. The 0.35BiScO3–0.65PbTiO3 composition was close to the MPB and had a Curie temperature of around 470°C. The electrical properties of BiScO3–PbTiO3 thin films showed a maximum at this composition. The dielectric permittivity of the 0.35BiScO3–0.65PbTiO3 thin film at the MPB was approximately 1700, with a dielectric loss tangent of less than 5% at room temperature. Furthermore, BiScO3–PbTiO3 thin films showed a typical ferroelectric polarization (P)–electric field (E) hysteresis loop. The remnant polarization (Pr) and coercive field (Ec) of the 0.35BiScO3–0.65PbTiO3 film were approximately 23 µC/cm2 and 70 kV/cm, respectively.