Preparation and optical characterization of sol-gel deposited Pb(Zr0.45Ti0.55)O3 films

Homogeneous crack-free lead zirconate titanate (Pb(Zr0.45Ti0.55)O-3: PZT 45/55) films were prepared by a chemically modified sol-gel process using lead acetate trihydrate, zirconium n-propoxide, and titanium isopropoxide precursors. The coating solutions were modified by the addition of diethanolamine. Single and multilayer films were deposited with a 2000 rpm spin rate on fused silica and MgO(100) substrates. Multiple spin coating with an intermediate heat treatment in air at 400 degreesC for 3 min between coatings was performed to obtain films up to 2 mum in thickness. The formation of the tetragonal perovskite structure was found to depend on the intermediate firing temperature, final annealing temperature, and annealing time. A 650 degreesC rapid thermal annealing treatment in oxygen was required to crystallize the PZT film into the perovskite structure. The films were characterized using optical spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and thermo-gravimetry and differential scanning calorimetry (TG-DSC). The optical constants of the PZT films were evaluated from spectral transmittance and reflectance measurements. Optical constants are presented over the visible and near infrared region.