Some electrical and optical properties of ferroelectric lead-zirconate–lead-titanate thin films

Abstract

Ferroelectric and transparent thin films of lead-zirconate–lead-titanate (PZT) were fabricated by rf diode sputtering. The substrates used were platinum, fused quartz, and In2O3-coated fused quartz, but no substantial difference on the film properties was observed. Films deposited at substrate temperatures below 300 °C were amorphous. At substrate temperatures of 350–450 °C the films crystallized in a pyrochlore structure. Films deposited at above 500 °C showed a perovskite structure and ferroelectric properties. The measured dielectric constant of the ferroelectric PZT was 751. Spontaneous polarization of the film was 26.1 μC/cm2 and the Curie temperature was 325 °C. The coercive field and remanent polarization were found to be 23.3 kV/cm and 20.4 μC/cm2, respectively. The refractive index of the perovskite PZT film was 2.36 at 6328 Å, and the absorption edge was found to be at 2950 Å. The edge of the pyrochlore film was at 3300 Å. Optical waveguiding properties of the PZT thin film were investigated at 6328 Å, but attenuation was impracticably large.