Fabrication and ferroelectric properties of sol–gel derived 1–1 intergrowth-superlattice-structured Bi3TiNbO9-Bi4Ti3O12 thin films

Abstract

1–1 intergrowth-superlattice-structured Bi3TiNbO9–Bi4Ti3O12 (BTN–BIT) ferroelectric thin films have been prepared on p-Si substrates by sol-gel processing. The precursor films are crystallized in the desired intergrown BTN–BIT superlattice structures by optimizing the processing conditions. Synthesized BTN–BIT thin films annealed below 750 °C are polycrystalline, uniform and crack-free, no pyrochlore phase or other second phase, and exhibited good ferroelectric properties. As the annealing temperature increases from 600 to 700 °C, both remanent polarization Pr and coercive electric field Ec of BTN–BIT thin films increase, but the pyrochlore phase in BTN–BIT films annealed above 750 °C will impair the ferroelectric properties. The BTN–BIT thin films annealed at 700 °C have a Pr value ~19.1μC/cm2 and an Ec value ~135 kV/cm.