Improvement of electrical properties of Sr-modified (Pb,Ca)TiO3 thin films grown by soft chemistry route

Abstract

Strontium and calcium-modified lead titanate (Pb0.70Ca0.15Sr0.15)TiO3 soft chemistry-derived thin films were prepared on platinum-coated silicon substrate by spin-coating method. Investigations were made on the structure, surface morphology and electrical properties of the film. The results by XRD and FE-SEM showed that the film exhibits a pure tetragonal perovskite phase and an average grain size of about 50-60 nm, respectively. Electrical measurements of a metal-ferroelectric-metal type capacitor exhibited a stable and switchable electrical polarization in the film. The structure of the Au/PCST/Pt capacitor showed well-saturated hysteresis loops at an applied voltage of 300 kV/cm with remanent polarization and coercive field values of 22 mu C/cm(2) and 100 kV/cm, respectively. At 100 kHz, the dielectric constant and the dielectric loss of the (Pb0.70Ca0.15Sr0.15)TiO3 thin film with thickness 240 nm were 528 and 0.05, respectively. (C) 2008 Elsevier Ltd. All rights reserved.