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

摘要

Bi_4Ti_3O_(12) (BIT) ferroelectric thin films with Dy~(3+) substitution (Bi_(4-x)Dy_xTi_3O_(12), x=0, 0.2, 0.4, 0.6, 0.8 and 1.0, respectively) were grown on Pt(111)/Ti/SiO_2/Si(100) substrates using sol-gel method. X-ray diffraction (XRD) and scanning electron microscopy (SEM) revealed that after annealing at 710℃ for 10 min, all Bi_(4-x)Dy_xTi_3O_(12) films became polycrystallites. Among all the deposited thin films, the Bi_(3.4)Dy_(0.6)Ti_3O_(12) specimen exhibits improved ferroelectric properties with the largest average remanent polarization (2Pr) of 53.06 μC/cm~2 under applied field of 400 kV/cm and fatigue free characteristics (16% loss of 2Pr after 1.5x10~(10) switching cycles), indicating that it is suitable for non-volatile ferroelectric random access memories applications.