Effect of deposition pressure on the dielectric properties of bismuth magnesium niobium titanium thin films prepared by RF magnetron sputtering

The Bi1.5Mg0.5Nb0.5Ti1.5O7 (BMNT) thin films with cubic pyrochlore structure were prepared on Pt/TiOx/SiO2/Si substrates by rf magnetron sputtering. The effects of deposition pressure on the structure and dielectric properties of BMNT thin films were investigated. As the deposition pressure decreases, the crystallinity becomes better, and the dielectric properties and tunability have an obvious improvement. The BMNT thin film deposited at 1 Pa exhibited a dielectric constant of 107.86, a tunability of 30.0% at 1 MV/cm, low tangent loss of 0.0017, and the largest FOM of 176.47. The excellent dielectric properties make BMNT thin films promising for potential tunable capacitor applications.