Electrical and optical properties of sol-gel derived Ca-modified PbTiO3 thin films

Calcium modified lead titanate (Pb0.76Ca0.24TiO3)(PCT76/24) sol-gel derived thin films have been prepared on ITO coated glass and quartz substrates by spin coating method. The films on quartz substrates have been used to study the optical properties and those on ITO coated glass substrates to study the electrical properties by preparing ferroelectric capacitors (MIM structures). The microstructure and surface morphologies of the films annealed at 650 °C have been studied by X-ray diffraction and atomic force microscope (AFM). Electrical measurements of metal-ferroelectric-metal type capacitor reveal the ferroelectric domain switching in the films. Also dependence of leakage current on applied voltage has been studied. The dependence of dielectric constant on temperature and hysteresis behavior have also been investigated and presented in this paper. The wavelength dispersion curve of thin films has been obtained from a transmission spectrum recorded by Cary spectrophotometer.