Linear and nonlinear optical properties of (Pb,La)(Zr,Ti)O3 ferroelectric thin films grown by radio-frequency magnetron sputtering

Abstract

Linear and nonlinear optical properties of lanthanum-modified lead zirconate titanate (Pb0.92La0.08)(Zr0.65Ti0.35)O3 (PLZT 8/65/35) ferroelectric thin films are presented in this paper. The PLZT ferroelectric thin films were grown on quartz substrates by radio-frequency magnetron sputtering at 650 °C. Their crystalline structure and surface morphologies were examined by x-ray diffraction and atomic force microscopy, respectively. It was found that the PLZT thin films exhibit well-crystallized perovskite structure and good surface morphology. The fundamental optical constants (the band gap energy, linear refractive index and absorption coefficient) were obtained through the optical transmittance measurements. A Z-scan technique was used to investigate the optical nonlinearity of the PLZT thin films on quartz substrates. The films display a strong third-order nonlinear optical effect. A large and negative nonlinear refractive index n2 is determined to be 1.21 × 10−6 esu for the PLZT thin films. All results show that the PLZT ferroelectric thin films have potential applications in nonlinear optical devices.