UC Santa Barbara

We report on the dielectric properties of BaxSr1xTiO3(BST) films grown by molecular beam epitaxy on epitaxial Pt bottom electrodes. Paraelectric films (x<0.5) exhibit dielectric losses that are similar to those of BST single crystals and ceramics. Films with device quality factors greater than 1000 and electric field tunabilities exceeding 1:5 are demonstrated. The results provide evidence for the importance of stoichiometry control and the use of a non-energetic deposition technique for achieving high figures of merit of tunable devices with BST thin films.