Improved dielectric performance of barium strontium titanate multilayered capacitor by means of pulsed laser deposition and slow injection sol–gel methods

A Pt/BST/NiFe/Cu multilayered capacitor was fabricated incorporating a polycrystalline Ba_0.5Sr_0.5TiO₃(BST) film deposited using the pulsed laser deposition technique. Qualitative X-ray diffraction analysis confirmed a perovskite structure for the deposited BST dielectric films which were fired at various temperatures. No intermediate phase was discernable with a post-annealing temperature of 750 °C and highly crystallized thin film was obtained at a post-annealing temperature of 800 °C. The fabricated capacitor with a BST film thickness of 665 nm exhibited respectable electrical performance with a dielectric constant, <i>k</i>of 657, and a dielectric loss, tan δ = 0.0137 at room temperature at an applied frequency of 1 MHz. The recorded charge storage density and leakage current density were 4.6 μC cm⁻²and 33 nA cm⁻², respectively, with ± 5 V bias.