Processing and properties of ferroelectric (Bi, La)4(Ti, Ge)3O12 thin films by chemical solution deposition

Ferroelectric (Bi, La)4(Ti, Ge)3O12 thin films have been prepared on Pt/TiOx/SiO2/Si substrates using metal–organic precursor solutions by the chemical solution deposition (CSD). The Bi3.25La0.75Ti2.9Ge0.1O12 (BLTG) precursor films were found to crystallize into the Bi layered perovskite Bi4Ti3O12 (BIT) as a single phase. The synthesized BLTG films revealed a random orientation having strong 0 0 l reflections. The BLTG thin films prepared at 700 °C showed a well-saturated P–E hysteresis loop with a remanent polarization, Pr of 12 μC/cm2 and a coercive field, Ec of 66 kV/cm at an applied voltage of 5 V. The surface morphology of the BLTG thin films was greatly improved by germanium (Ge) doping compared with that of nondoped Bi3.35La0.75Ti3O12 (BLT) films.