Structure, ferroelectric, and enhanced fatigue properties of sol–gel-processed new Bi-based perovskite thin films of Bi(Cu_1/2Ti_1/2)O₃–PbTiO₃

Bi-based perovskite ferroelectric thin films have wide applications in electronic devices due to their excellent ferroelectric properties. New Bi-based perovskite thin films Bi(Cu_1/2Ti_1/2)O₃–PbTiO₃ (BCT–PT) are deposited on Pt(111)/Ti/SiO₂/Si substrates in the present study by the traditional sol–gel method. Their structures and related ferroelectric and fatigue characteristics are studied in-depth. The BCT–PT thin films exhibit good crystallization within the phase-pure perovskite structure, besides, they have a predominant (100) orientation together with a dense and homogeneous microstructure. The remnant polarization (2P_r) values at 30 μC/cm² and 16 μC/cm² are observed in 0.1BCT–0.9PT and 0.2BCT–0.8PT thin films, respectively. More intriguingly, although the polarization values are not so high, 0.2BCT–0.8PT thin films show outstanding polarization fatigue properties, with a high switchable polarization of 93.6% of the starting values after 10⁸ cycles, indicating promising applications in ferroelectric memories.