Ferroelectric and fatigue-free properties of Au/(Bi,La)4Ti3O12/ITO thin film capacitors by pulsed laser deposition

Ferroelectric Bi_3.25La_0.75Ti₃O₁₂ (BLT) thin films were deposited on indium-tin-oxide (ITO) coated glass substrates by pulsed-laser-ablation method. Films deposited at 400 °C and annealed at 650 °C resulted in remnant polarization and coercive field values of 14-16 μC/cm² and 90-100 kV/cm, respectively. The fatigue measurements were conducted until 1 × 10¹¹ cycles but the individual switched and unswitched polarizations showed unequal magnitudes. Such an unequal switching polarization proves that an extrinsic effect mainly associated with the electrode exists in this thin film capacitor. The overall switching polarizations showed no polarization degradation, suggesting that BLT films are fatigue resistive even on hybrid-metal-oxide electrodes.