Sol-gel derived ferroelectric thin films of LiTaO₃ on SiO₂/Si substrate

Thin films of LiTaO₃ are deposited on silica-on-silicon substrates by sol-gel processing. The films are characterized by means of X-ray diffraction, atomic force microscopy, Raman spectroscopy, and variable angle spectroscopic ellipsometry. The experimental results show that crystallization of the deposited films starts at 600°C. The films annealed at 600 and 700°C have a nanocrystalline nature with the grain size ranging from 21nm to 114nm. The fine crystalline size and the pure ferroelectric phase of the films make them potential candidates for E-O and A-O waveguide applications.