Ferroelectric and Electronic Properties of Undoped-Bi4Ti3O12 Thin Film on TiO2 Anatase Layer

Abstract

Bi 4 Ti 3 O 12 (BIT) thin films with TiO 2 anatase layer have been prepared on the Pt/Ti/SiO 2 /Si substrates by metalorganic chemical vapor deposition. The BIT thin films with TiO 2 anatase layer exhibit highly a- and b-axes orientation, although the BIT thin film with no layer exhibits a c-axis orientation. The interdiffusion between BIT thin film and Pt substrate was prevented by inserting TiO 2 anatase layer. The ferroelectricity depends on the thickness ratio of the BIT thin film to the TiO 2 anatase layer, indicating that the TiO 2 anatase layer acts not as barrier layer but as an initial nucleation layer. When the thickness ratio was fixed at [(BIT)/(TiO 2 )] = 15, the remanent polarization (P r ) and the coercive field (E c ) were 2P r = 81.6 μC/cm 2 and 2E c = 250 kV/cm, respectively. The dielectric constant (ϵ r ) is 160.