Electromechanical properties of BaTiO3-xBaSnO3 thin films prepared via combinatorial sputtering

(1−x)BaTiO3-xBaSnO3 (BT-xBS, 0≤x≤0.20) perovskite thin films were deposited on Pt/Ti/Si substrates with uniaxial graded composition by using a dual-target combinatorial sputtering technique. These films were highly (101)-oriented and showed strong composition dependence in their electromechanical properties. The maximum value of the relative dielectric constant was 925 at around x=0.028, where the transverse piezoelectric coefficient |e31, f| also peaked at about 1.5-1.9 C/m2. This |e31, f| value is higher than those of epitaxial BaTiO3 thin films. Our results indicate that BT-xBS is a promising substitute of lead-based perovskites for applications in piezoelectric MEMS devices.