Enhanced dielectric properties of barium strontium titanate thin films by doping modification

Barium strontium titanate (BaxSr1-xTiO3, BST) thin films have large dielectric constant, low dielectric loss, especially the high dielectric tunability, which make them prospective candidates for microwave tunable applications. Resent developments in BST thin films by doping modification are reviewed. The A-site doping, B-site doping, and both sites codoping modifications are summarized and analyzed, respectively. The comparison of dielectric properties and microstructure of the BST thin films with different sites doping modifications is critically analyzed. The single A-site or B-site doping modification cannot obtain the BST thin films with balanced enhancement of the dielectric properties. However, the different elements codoping in both A-site and B-site of BST thin films is demonstrated to be an effective method to achieve balanced dielectric property optimization.