Highly (111)-oriented (Ba,Sr)TiO3 (BST) thin films were deposited on BaPbO3 electrode at the different deposition temperatures of 450, 500, and 550 degrees C by radio frequency magnetron sputtering. It is found that the crystallinity and grain size of BST films improves with higher deposition temperature. The microstructure of the BST films showed multigrain structure through the film thickness. With the increase of deposition temperature, the dielectric constant, tunability, figure of merit, and leakage current density increase from 272, 43%, 12, and 8 x 10(-9) A/cm(2) to 391, 55%, 19, and 6.5 x 10(-8) A/cm(2), respectively. The BST films showed grain boundary limited conduction behavior because of the small-grained microstructure. (c) 2005 The Electrochemical Society. All rights reserved.