Pulsed-laser deposited amorphous-like PZT thin-films: Microstructure and optical properties

Amorphous lead-zirconate-titanate (Pb0.97Nd0.02(Zr0.55Ti0.45)O-3, PNZT) thin-films were grown on single-crystal MgO(1 0 0) substrates at room temperature by pulsed laser deposition (PLD). Part of PNZT films was left as-deposited amorphous and others were post-annealed at temperatures from 100 to 400 degrees C. X-ray diffraction (XRD) and scanning probe rnicroscopy(SPM) were used to characterize the microstructure. Optical properties were analyzed using spectrophotometry at UV-vis-NIR and prism-coupler method at 633 nm wavelengths. Initially, films were amorphous with a broad XRD peak around 2 theta approximate to 29.7 degrees. As the post-annealing temperature increased above 250 degrees C, the amorphous peak started to shift towards lower 20-angles and got narrower indicating of decreasing interatomic spacing and possible glass transformation. At the same time, the transmittance at all wavelengths increased remarkably, although no crystal structure was detected by XRD. Also, sharp optical TE0 modes with full-width half-maximum (FWHM) values of Delta beta approximate to 0.00067 could be coupled into these films. (C) 2009 Elsevier Ltd. All rights reserved.