Preparation and Characterization of LiNbO_3 Thin Films Derived from Metal Carboxylate Gels

摘要

Lithium niobate thin films have been deposited on Pt/Ti/SiO_2/Si substrates by the Pechini method from metal carboxylate gels and heat-treated at temperatures ranging from 400 to 600℃. 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 LiNbO_3 films demonstrate a ferroelectric hysteresis loop. The remanent polarization (P_r) and coercive field (E_c) are 17.89 μC/cm~2 and 35.23 kV/cm, respectively.