Crystallization and electrical properties of Bi_4Ti_3O_(12) films derived from bismuth acetate and bismuth nitrate precursor solutions

摘要

Ferroelectric Bi_4Ti_3O_(12) thin films were prepared by the sol-gel method to examine the effect of precursors on the variation of ferroelectric properties. Two kinds of Bi_4Ti_3O_(12) sol-gel precursor solutions were synthesized by dissolving bismuth acetate and bismuth nitrate in glacial acetic acid and then adding titanium acetate. The films were deposited on Pt coated Si substrates by the spin-coating method and crystallized by double heat-treatment. The Ps, the Pr, and the Ec values of the film derived from the Bi-acetate were 34.8 mu C/cm~2, 16.2 mu C/cm~2, and 128 kV/cm, respectively. The Ps, the Pr, and the Ec of the films from the Bi-nitrate were 14.2 mu C/cm~2, 5.7 mu C/cm~2, and 105 kV/cm, respectively. The Bi_4Ti_3O_(12) films prepared from the Bi-acetate revealed better ferroelectricity and resistivity compared to those obtained from the Bi-nitrate.