Dielectric tunable properties of BaTi1-xSnxO3 thin films derived from sol-gel soft chemistry

Dense and homogeneous BaTi1-xSnxO3 (BTS, x = 0.1, 0.15, 0.2, 0.25, and 0.3) thin films are prepared by sol-gel and spin-coating soft chemistry, which is a simple, repeatable and quality-controlled method. The effects of Sn content on the structure and dielectric properties are systemically studied. The BTS thin film with 0.25 mol% Sn is found to exhibit a moderate dielectric constant of 225–398, a high tunability of 43.3% under a low bias electric field of 8 kV/mm, and a corresponding leakage current density of 6.2×10−8 A/cm2. These improvements are a result of the enhancement in relaxor characteristics, the good crystallization conditions leading to a denser and more uniform structure, as well as the inhibition of oxygen vacancies resulting from the suppression of electronic transition from Ti4+ to Ti3+. The findings reported in this work provide a simple and effective way to prepare excellent tunable thin films that show great potential for the development of electrically tunable components and devices.