Ferroelectric (Ba,Sr)TiO3 and Pb(Zr,Ti)O-3 thin films prepared by pulsed laser deposition

Barium strontium titanate, (Ba, Sr)TiO3 (BST), and lead zirconium titanate, Pb(Zr, Ti)O-3 (PZT) thin films were synthesized on indium-tin-oxide coated glass substrates using pulsed laser deposition process. Perovskite structu re of these materials can be obtained by controlling the substrate temperat ure at 500-620 degreesC. All the films possess good ferroelectric propertie s at low frequency regime. When both films were deposited at 500 degreesC a nd measured at 10 GHz, the dielectric constant is epsilon (tau)congruent to 1000 for (Ba, Sr)TiO3 thin films and is epsilon (tau)congruent to 550 for Pb(Zr, Ti)O-3 thin films. Optical transmission spectroscopies show that the Pb(Zr, Ti)O-3 thin films exhibit larger refractive index ((n)(PZT) = 2.1-2 .8) than the (Ba, Sr)TiO3 thin films ((n)(BST) = 1.95-2.15), which is ascri bed to the heavier mass of the constituents in the Pb(Zr, Ti)O-3 thin films . The (Ba, Sr)TiO3 thin films also Possess Much lower absorption coefficien t (kappa) than the Pb(Zr, Ti)O-3 thin films, which indicates that the (Ba, Sr)TiO3 thin films contain less intrinsic defects than the Pb(Zr, Ti)O-3 ma terials. (C) 2001 Elsevier Science Ltd. All rights reserved.