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 f or epitaxially crystallized (Ba0.5,Sr0.5)TiO3 (BST) films deposited on Pt/MgO and YBaCu3O7-x (YBCO)/MgO substrates by the laser ablation tec hnique. Rutherford backscattering spectroscopy analysis shows that thi n films on Pt/MgO have almost the same stoichiometric composition as t he target material. Films deposited at 600-degrees-C exhibited an exce llent epitaxial growth, a dielectric constant of 430, and a dissipatio n factor of 0.02 at 10 kHz frequency. They have a charge storage densi ty of 40 fC/mum2 at an applied electric field of 0.15 MV/cm. Leakage c urrent density of BST thin films on Pt/MgO was smaller than on YBCO/Mg O. Their leakage current density is about 0.8 muA/cm2 at an applied el ectric field of 0.15 MV/cm.