Preparation and properties of Bi₄Ti₃O₁₂ thin films grown at low substrate temperatures

Bismuth titanate (Bi₄Ti₃O₁₂) thin films were deposited on a (100) silicon substrate at a substrate temperature of 500°C, using rf magnetron sputtering. Ferroelectric Bi₄Ti₃O₁₂ thin films were deposited on the pyrochlore phase buffer layer. The pyrochlore phase buffer layer was effective for lowering substrate temperature and suppressed the growth of the plate-like grains. The apparent remanent polarization and the apparent coercive field of this film at the measurement frequency of 50 Hz were estimated to be 2.4 μC cm^-2 and 2.3 kV cm^-1, respectively. The apparent remanent polarization was degraded to approximately 40% of the initial value by 1 × 10⁶ switching cycles. The capacitance-voltage hysteresis loop of Bi₄Ti₃O₁₂ thin film on silicon substrate is observed to correspond to ferroelectricity.