Microwave Dielectric Properties Of Graded Barium Strontium Titanate Films

Compositionally graded barium strontium titanate (BaxSr1-xTiO3 or BST) multilayers (5 mol % MgO doped and undoped) were prepared via metallo-organic solution deposition on Pt-Si substrates and characterized electrically at 0.5, 5, and 10 GHz. For the undoped BST multilayers, the small-signal dielectric response, tunability, and the loss tangent at 10 GHz were 261, 25% at 1778 kV/cm, and 0.078, respectively. On the other hand, the Mg-doped BST multilayers displayed a significant improvement in the loss characteristics at 10 GHz (0.039) but the dielectric response and its tunability were lower (189 and 15%, respectively, at 1778 kV/cm). (c) 2008 American Institute of Physics.