Microstructure and ferroelectric properties of dysprosium-doped bismuth titanate thin films

Bi4Ti3O12 (BIT) ferroelectric thin films with Dy3+ substitution (Bi4−xDyxTi3O12, x = 0, 0.2, 0.4, 0.6, 0.8 and 1.0, respectively) were grown on Pt(111)/Ti/SiO2/Si(100) substrates using sol–gel method. X-ray diffraction (XRD) and scanning electron microscopy (SEM) revealed that after annealing at 710 °C for 10 min, all Bi4−xDyxTi3O12 films became polycrystallites. Among all the deposited thin films, the Bi3.4Dy0.6Ti3O12 specimen exhibits improved ferroelectric properties with the largest average remanent polarization (2Pr) of 53.06 μC/cm2 under applied field of 400 kV/cm and fatigue free characteristics (16% loss of 2Pr after 1.5 × 1010 switching cycles), indicating that it is suitable for non-volatile ferroelectric random access memories applications.