Preparation and Characterization of LiNbO₃ Thin Films Derived from Metal Carboxylate Gels

Lithium niobate thin films have been deposited on Pt/Ti/SiO2/Si substrates by the Pechini method from metal carboxylate gels and heat-treated at temperatures ranging from 400 to 600°C. The thermal decomposition of the metal carboxylate precursor gels has been studied by differential thermal analysis and thermogravimetry. The products derived from calcination of the gels at different temperatures have been characterized by Fourier transform infrared, Roman spectrum and X-ray diffraction. Scanning electron microscopy analysis shows the surface of the films to be smooth, dense and crack-free. Electric properties measurement indicates that the LiNbO3 films demonstrate a ferroelectric hysteresis loop. The remanent polarization (Pr) and coercive field (Ec) are 17.89 μC/cm2 and 35.23 kV/cm, respectively.