Dielectric properties of Barium Strontium Titanate thick films fabricated by aerosol-deposition method

초록

Barium strontium titanate (Ba0.7Sr0.3TiO3) (BST) materials have received an increased attention due to various applications. The BST films were found to have lower curie temperature than BaTiO3 of 120℃. BST films with nano-size grains were fabricated by aerosol-deposition method and their dielectric properties were characterized. As AD is a room-temperature process based on shock loading solidification resulting from the collision of fine ceramic particles on the silicon wafer, the nano-sized grains can be deposited on the silicon wafer without occurring the oxidation of surface. The BST films showed nano-sized grains and dense microstructure. The AD BST thick films were annealed at 500 and 600℃ for 2h to increase the crystallinity. Compared with pure BaTiO3(BT), the phase transition temperature of BST was decreased due to Sr2+ addition. According to XRD pattern, 2𝜃degree was shifted to higher angle because X-tal structure was changed due to the strong shock by aerosol-deposition. After annealing, saturation polarization was increased from 9.5 μC/cm2 of AD film to 17.5μC/cm2 of AD BST film annealed at 600℃.