Optical scattering of nanocrystalline Pb(Zr_xTi_(1-x))O_3 films

摘要

Optical characterization methods, like spectrophotometry at UV-vis-NIR wavelengths and prism-coupler method, were applied to polycrystalline Pb(Zr_xTi_(1-x))O_3 thin films at various thicknesses. Thin films were deposited at room temperature by pulsed laser deposition on MgO (100) substrates and post-annealed at different temperatures. X-ray diffraction and atomic force microscopy were used to characterize the crystal structure and surface morphology of the thin films, respectively. Well oscillating transmission with a sharp fall near the absorption edge was found in films with high orientation and low surface roughness. Changes in the surface morphology and crystal orientation were found to modulate optical interference maxima and minima of the transmittance spectra and to increase the width of the TE_0 mode (DELTA beta approx = 0.06) indicating an increase in the scattering losses of the films. Single-phase oriented films had sharpest coupling values (DELTA beta approx = 0.005) of the TE_o mode.