Ferroelectric and pyroelectric properties of (Na0.5Bi0.5)TiO3–BaTiO3 based trilayered thin films

Trilayered Bi3.25La0.75Ti3O12 (25 nm)/(Na0.5Bi0.5)0.94Ba0.06TiO3 (300 nm)/Bi3.25La0.75Ti3O12 (25 nm) and Pb(Zr0.4Ti0.6)O3 (25 nm)/(Na0.5Bi0.5)0.94Ba0.06TiO3 (300 nm)/Pb(Zr0.4Ti0.6)O3 (25 nm) thin films without undesirable phases have been deposited on Pt/Ti/SiO2/Si substrates. It was found that the Bi3.25La0.75Ti3O12 and Pb(Zr0.4Ti0.6)O3 layers are very effective to inhibit the charge transport in the trilayered films. Much better insulating properties than those of (Na0.5Bi0.5)0.94Ba0.06TiO3 films have been achieved in the trilayered films. The trilayered films show good dielectric, ferroelectric and pyroelectric properties. Remnant polarizations 2Pr of 16 µC/cm2 and 34 µC/cm2, pyroelectric coefficients of 4.8 × 10− 4 C m− 2 K− 1 and 7.0 × 10− 4 C m− 2 K− 1 have been obtained for the Bi3.25La0.75Ti3O12/(Na0.5Bi0.5)0.94Ba0.06TiO3/Bi3.25La0.75Ti3O12 and Pb(Zr0.4Ti0.6)O3/(Na0.5Bi0.5)0.94Ba0.06TiO3/Pb(Zr0.4Ti0.6)O3 thin films, respectively. The trilayered films are promising candidates for sensor and actuator applications.