Investigation on Tunable Performance of BMN / BST Multilayer and BMN – BST Composite Thin Films

The BMN/BST multilayer and BMN–BST composite thin films have been fabricated by pulsed laser deposition on Au/TiO x /SiO 2 /Si substrate. The multilayer thin films comprising one, two, and four periodic compositional Bi 1.5 MgNb 1.5 O 7 /Ba 0.6 Sr 0.4 TiO 3 (BMN/BST) layers (PCBLs) have been elaborated with the final same thickness. The four PCBLs show the largest dielectric constant of ~168 and tunability of 40.6% at a maximum applied bias field of 0.67 MV/cm and the lowest loss tangent of ~0.006, whereas the figure of merit (FOM) is 72. The BMN–BST composite thin films exhibit medium dielectric constant of ~238, low loss tangent of ~0.0053, and superior tunable dielectric properties at room temperature. Calculations of tunability and FOM display a maximum value of 49.3% at 670 kV/cm and ~88, respectively.