Ferroelectric and dielectric properties of lead zirconate titanate multilayers

Ferroelectric and dielectric properties of the PbZr_0.38Ti_0.62O₃(PZT) multilayer with a unique structure were explored. Compared with the uniform PZT thin films, the PZT multilayer with alternating dense-PZT and porous-PZT layers exhibits an enhancement both in ferroelectric and dielectric performances. The PZT multilayer has an average remanent polarization of 42.3 C/cm² and an average coercive field of 43 kV/cm under an applied voltage of 100 V. The large value of remanent polarization is attributed to the effective relaxation of the tensile stress in film due to large film thickness and porous structure. The apparently relative dielectric constant of the PZT multilayer is more than 2000 at room temperature and low frequency limit. More interestingly, two distinct dielectric relaxations have been observed in the PZT multilayer in the investigated frequency range. The low-frequency loss peak originates from space charge polarization, while the high-frequency dielectric response following an Arrhenius-law is expected to be related to the dipolar defect complexes associated with oxygen vacancies V_ö.