The optimization of electric properties of multilayered BNT–BT–ST/BCST thin films by configuration

Abstract

The 0.755Bi_0.5Na_0.5TiO₃–0.065BaTiO₃–0.18SrTiO₃/Ba_0.98Ca_0.02Ti_0.96Sn_0.04O₃ (BNT–BT–ST/BCST) multilayered thin films, consisting of BNT–BT–ST layers and BCST layers, were prepared by using the sol–gel processing technique. The structure, leakage current, dielectric and piezoelectric properties of the multilayered thin films were investigated. Compositionally graded elemental profiles between individual BNT–BT–ST and BCST layers were achieved. The electric properties of the BNT–BT–ST/BCST multilayered thin films could be affected by the periodic layers. As a result, with an increase in periodic layers of the BNT–BT–ST/BCST multilayered thin films, the leakage current and dielectric loss were significantly reduced; moreover, the piezoelectric responses could be maintained at a high level (d₃₃ = 130–150 pm V⁻¹). This demonstrated the possibility to improve certain properties of the leakage current and dielectric loss for multilayered thin films, which could be exploited for functional devices that demand high quality.