Ferroelectric properties and fatigue behavior of heteroepitaxial PbZr1-xTixO3 thin film fabricated by hydrothermal epitaxy below Curie temperature

A heteroepitaxial PbZr1-xTixO3 (PZT) thin film was fabricated by means of hydrothermal epitaxy at 210 degrees C below Curie temperature without undergoing the paraelectric to ferroelectric phase transition. From transmission electron microscope and piezoresponse force microscope observations, it was confirmed that the fabricated PZT thin films had only a -c monodomain without an a domain in the as-synthesized state. The polarization-electric-field hysteresis curve and the fatigue behavior of the heteroepitaxial PZT capacitor with a Pt top and n-type semiconductor bottom electrode was observed. The remanent polarization 2P(r) of the PZT capacitor was about 63 mu C/cm(2). This value was much lower compared to that of the PbTiO3 capacitor, which was also fabricated by means of hydrothermal epitaxy at 160 degrees C below Curie temperature. It was suggested that a lower polarization of the PZT capacitor was due to the nonswitchable interfacial layer grown in the initial growth stage. However, this layer did not exert an influence on the fatigue behavior of the PZT capacitor: the PZT capacitor with an ordinary Pt top electrode and a Nb-doped SrTiO3 semiconductor bottom electrode revealed fatigue-free behavior in up to 10(11) switching cycles.