Significant Enhancement of Bi3.45La0.75Ti₃O₁₂Ferroelectricity Derived by Sol-Gel Method

The ferroelectricity of sol-gel derived 80-nm Bi3.45La0.75Ti3O12 (BLT) films was significantly enhanced by low-pressure baking during the sol-gel process. The ferroelectricity enhancement was caused by the low-pressure baking after the drying process in air and before the crystallization of the dried gel. The maximum remanent polarization (Pr) was 27.2 µC/cm2, which was achieved after baking at 1.3 kPa oxygen pressure. The coercive field of 54.3 kV/cm was also achieved at the same time. This Pr value is 2.3 times larger than the value attainable with the usual 1-atm baking process. The saturation property of the same capacitor proved that +/-2 V operation is possible. It was also found that the enhanced polarization is fatigue-free up to 1010 switching cycles.