Ba(0.6)Sr(0.4)TiO(3)-MgO Thick Films Deposited by Electrophoretic Deposition for Tunable Microwave Device

摘要

We report on the structural, dielectric, and optical properties of barium strontium titanate-magnesium oxide composite (BST-MgO) thick films fabricated by the electrophoretic deposition (EPD) technique. The structure and morphology of the films were analyzed by x-ray diffraction and scanning electron microscopy, respectively. The films were optically characterized via FT-Raman spectroscopy. The dielectric measurements were conducted on MIM capacitors using platinum as the top and bottom electrodes. The typical small signal dielectric constants of Ba(0.6)Sr(0.4)TiO3 and Ba(0.6)Sr(0.4)TiO3-20 weight-percent MgO thick films, measured at an applied frequency of 1 MHz, were 603 and 327, respectively. The corresponding values of dissipation factor were 0.029 and 0. 002, respectively. A high dielectric tunability of 17.3% was obtained for Ba(0. 6)Sr(0.4)TiO3 thick films at an applied electric field of 20 kV/cm. The dielectric properties of the present thick films were comparable to those of the bulk ceramics, suggesting their suitability for high-frequency, wide band voltage tunable device applications.