Analysis of fatigue characteristics in Fe-doped Pb(Zr0.52Ti0.48)O3 thin films by switching currents

The polarization fatigue for ferroelectric Pb(Zr0.52Ti0.48)O-3 (PZT) thin films has a known relation with oxygen vacancies occurring in the films during fabrication processes. Fe-doped PZT thin films were intentionally deposited with consideration for the effects of oxygen vacancies regarding fatigue using rf-magnetron sputtering. The remanent polarization is suppressed to half its initial value after 10(9) bipolar switching cycles. From the observance of the switching currents with consideration to applied voltages, switching characteristics in the films were studied by fitting using the Kolmogorov-Avrami (K-A) theory. It was revealed from the switching currents as a function of fatigue cycles that the quantity of switched charges decreased with increasing switching cycles, but the dimensionality with respect to domain growth was unchanged as compared to its initial value. The velocities of domain wall motions before and after fatigue were also unchanged, indicating that the motion of the domain walls by applied pulse voltages was not an additional obstacle concerning fatigue processes. Therefore,in the case of polarization fatigue by subjecting to electric cycles; the domain states in these films may not be affected by the fatigue.