Ferroelectric (Ba,Sr)TiO3 and Pb(Zr,Ti)O3 thin films prepared by pulsed laser deposition

Barium strontium titanate, (Ba, Sr)TiO3 (BST), and lead zirconium titanate, Pb(Zr, Ti)O3 (PZT) thin films were synthesized on indium-tin-oxide coated glass substrates using pulsed laser deposition process. Perovskite structure of these materials can be obtained by controlling the substrate temperature at 500–620°C. All the films possess good ferroelectric properties at low frequency regime. When both films were deposited at 500°C and measured at 10 GHz, the dielectric constant is ετ≅1000 for (Ba, Sr)TiO3 thin films and is ετ≅550 for Pb(Zr, Ti)O3 thin films. Optical transmission spectroscopies show that the Pb(Zr, Ti)O3 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 ascribed to the heavier mass of the constituents in the Pb(Zr, Ti)O3 thin films. The (Ba, Sr)TiO3 thin films also possess much lower absorption coefficient (κ) than the Pb(Zr, Ti)O3 thin films, which indicates that the (Ba, Sr)TiO3 thin films contain less intrinsic defects than the Pb(Zr, Ti)O3 materials.