Preparation of thin‐film (Ba0.5,Sr0.5)TiO3 by the laser ablation technique and electrical properties

The chemical composition and electrical properties were investigated for epitaxially crystallized (Ba0.5,Sr0.5)TiO3 (BST) films deposited on Pt/MgO and YBa2Cu3O7−x (YBCO)/MgO substrates by the laser ablation technique. Rutherford backscattering spectroscopy analysis shows that thin films on Pt/MgO have almost the same stoichiometric composition as the target material. Films deposited at 600 °C exhibited an excellent epitaxial growth, a dielectric constant of 430, and a dissipation factor of 0.02 at 10 kHz frequency. They have a charge storage density of 40 fC/μm2 at an applied electric field of 0.15 MV/cm. Leakage current density of BST thin films on Pt/MgO was smaller than on YBCO/MgO. Their leakage current density is about 0.8 μA/cm2 at an applied electric field of 0.15 MV/cm.