Synthesis, optical and ferroelectric properties of PZT thin films: experimental and theoretical investigation

PbZr0.40Ti0.60O3 (PZT40/60) thin films with ferroelectric and dielectric properties have been grown on Pt/Ti/SiO2/Si and LaAlO3 (100) substrates using the chemical solution deposition method. These films have been characterized by different techniques such as X-ray diffraction (XRD), Raman, infrared and optical transmittance measurements. The transmittance curve of the PZT40/60 thin films on a LaAlO3 (100) substrate showed an optical band gap of 4.03 and 3.10 eV for the direct and indirect transition processes, respectively. To complement experimental data, first principles calculations at the DFT-B3LYP level were performed on periodic model systems of PbTiO3 and PZT40/60 to provide an insight into structural, optical and electronic behavior. The band gap of the PZT40/60 system for PbO and ZrO2 terminations is in agreement with trends of experimental data and results in smaller values than the band gap calculated for the PbTiO3 system.