Fatigue effects of metal-doped PZT thin films

Publisher Website
Google Scholar
Abstract
In order to investigate the fatigue effects of ferroelectric thin films, lead zirconate titanate (PZT) thin films doped Fe3+, Ni2+, Nd3+, and Nb5+ were fabricated by using rf-magnetron sputtering and sol-gel methods. The fatigue measurements were performed with bipolar switching pulses. All of the doped PZT thin films showed similar behavior on bipolar pulses in which polarization abruptly decreased around 106 Hz. There was no apparent difference between doped and undoped PZT in fatigue characteristics. The samples were refreshed to the initial state when DC bias voltage of - 19 V was applied to the top electrode of the fatigued samples for 100 sec. However, they were not refreshed in case of DC bias voltage of +19 V. The coercive field slightly increased from the initial state. It was noted that an accumulation of oxygen vacancy caused by internal field at ferroelectric-electrode interfaces, platinum bottom electrode, plays an important role in the fatigue mechanism. The results suggests that the samples were refreshed to the initial state due to the diffusion of the oxygen vacancy into the thin films when we applied DC bias voltage of - 19 V.