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

Abstract

PbZr_0.40Ti_0.60O₃ (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.