Enhanced dielectric tunability in barium titanate thin films with boron additions

Boron incorporation in 650 nm thick polycrystalline BaTiO3 films results in grain growth and dramatic dielectric response improvements. For levels between 0% and 3%, average grain size is increased from 150 to 200 nm and the maximum permittivity values are nearly doubled, with tunabilities increased to greater than 90% while maintaining high field loss tangents below 0.03. These results demonstrate a pathway for microstructure engineering and property optimization in refractory electroceramic oxide thin films without increasing the thermal budget.