In situ electrical-field-induced growth and properties of Bi3TiNbO9 ferroelectric thin films

With ${\mathrm{Bi}}_3{\mathrm{TiNbO}}_9$ (BTN) ferroelectric samples, in situ electrical-field-induced growth of ferroelectric thin films was demonstrated to control the films’ microstructure and manipulate their ferroelectric properties. BTN films on $\mathrm{Ti}/{\mathrm{SiO}}_2/\mathrm{Si}$ substrates were grown at a relatively low temperature (650 °C) with a biased electrical field during pulsed-laser deposition. The (001) orientation of the films, which makes no contribution to their polarization, was effectively reduced by the in situ electrical field of strength of 70 V/cm. This results in a large increase of remnant polarization from 1.1 to 6.2 μC/cm², and reduction of the coercive field from 70 to 50 kV/cm, comparing the films grown freely under the same condition. Furthermore, the films showed an excellent fatigue-free property of up to ${10}^{10}$ switching cycles.