Dielectric properties of (Ba,Sr)TiO{sub 3} films by RF sputtering

The dielectric properties of (Ba,Sr)TiO{sub 3}(BST) thin films prepared by RF sputtering method, were investigated. Polycrystalline film structure and grain size were estimated by transmission electron microscopy (TEM) and Xray diffraction. The dielectric constant of BST films depends on their grain size rather than thickness of the film. A broad maximum in the temperature dependence of the dielectric constant of the films was observed, and Curie temperature was not clear. No hysteresis was observed in a D-E curve of the film at 77K.