Effects of switching pulse width and stress on properties of Bi_3.25La_0.75Ti₃O₁₂ thin films

Polycrystalline ferroelectric Bi_3.25La_0.75Ti₃O₁₂ thin films are prepared on Pt/Ti/SiO₂/Si substrates by the conventional metalorganic decomposition method. It is observed that with the increase of switching pulse width, the remnant polarisation and the coercive field increase. A wider switching pulse can result in poorer fatigue properties, which comes from more charged defects diffusing to and being trapped on domain walls. On the other hand, when the compressive stress is applied to films, the fatigue properties can be improved. This phenomenon is due to the reorientation of domains under stress.