Synthesis and Electrical Properties of BNT((Bi_1/2Na_1/2)TiO₃) Ferroelectric Thin Films by LSMCVD Technique

Abstract

This study is to synthesize lead-free ferroelectric material, (Bi_1/2Na_1/2)TiO₃ using the Liquid Sprayed Mist Chemical Vapor Deposition (LSMCVD) technique. The precursor solution was made from Bi₂O₃, Na₂CO₃, HNO₃, titanium tetra iso-propoxide(TTIP) and 2-methoxyethanol. The mist of precursor solution was carried into a furnace by argon gas. Then, the mist was vaporized and deposited on two different substrates of Si(100) and (111)Pt/TiO₂/SiO₂/Si(100) under an oxygen atmosphere. The concentration of the precursor solution was 0.02 M. The deposition temperature and time were varied in the range of 400-600°C and 30-90min. (Bi_1/2Na_1/2)TiO₃ thin film had preferred orientations of (110). The thickness of the thin film deposited was 35-162nm. The remnant polarizations (2Pr) and the dielectric constant were 5.664-2.308μC/cm², 50-350, respectively.