Stress Effect on the Tuning Properties of Ba[sub 0.5]Sr[sub 0.5]TiO[sub 3] Thin Films

Ferroelectric thin films are currently being used to develop tunable microwave circuits based on the electric-field dependence of the dielectric constant. Perovskite thin films were deposited on and substrates by radio frequency magnetron sputtering. Extensive X-ray diffraction studies exhibit good in-plane relationship of (LSCO). At the applied voltage of 7 V, the tunability values of barium strontium titanate (BST) films grown on Pt and LSCO/Pt were nearly 2.2:1 and 2.8:1, respectively. The change of dielectric properties in BST/LSCO and BST/Pt is attributed to the change in the film stress and the film orientation.