Properties of Pb(Zr0.92Ti0.08)O3 thin films deposited by sol-gel

Lead zirconate-titanate (PZT) thin films with Zr/Ti ratio of 92/8 were deposited by sol-gel on Pt coated silicon and single crystal MgO(100) substrates. In case of the films deposited on Pt the perovskite structure is established only after oxygen annealing, while for the films deposited on MgO annealing in air is enough. The films are polycrystalline with preferred orientation that is substrate dependent ((110) on Pt and (100)/(200) on MgO). Average values of 2.10 muC/cm(2) and 78 kV/cm were obtained for remnant polarization and coercive field, respectively. The I-V characteristic at low-to-intermediate electric fields is controlled by thermionic emission, but the Schottky representation is Ln(current)-(voltage)(1/4), implying that the film behaves like a semiconductor and not like an insulator. From transmission-reflectance measurements a value of 3.85 +/- 0.05 eV was estimated for the band gap, while the refraction index in the transparency region was found to be 2.6. A pyroelectric signal was detected on as grown films, making them attractive for infrared detection. (C) 2003 Elsevier B.V. All rights reserved.