Enhanced polarization switching characteristics of Pb(Zr0.5Ti0.5)O3-Pt nanocomposite thin films

The effect of nanoscale Pt particles embedded in ferroelectric matrix on the polarization switching characteristics of Pb(Zr0.5Ti0.1)O-3 (PZT) thin films of low thickness was investigated. Two different nanocomposite structures of PZT-Pt thin films were fabricated for the study. The first one incorporated a single layer of Pt nano-particles embedded in the PZT film, which was formed by annealing an ultrathin Pt layer that had been inserted into the middle of the deposited PZT. The other one had Pt nano-particles embedded uniformly and coherently in the lattice of the PZT matrix, which was generated by annealing the cosputtered films of PZT and Pt. The electric field applied on the films can be locally intensified near the embedded Pt particles, which markedly enhances the polarization switching characteristic of the above PZT-Pt nanocomposite films. Accordingly, a satisfactorily higher remanent polarization was obtained than exhibited by normal PZT films, but the coercive field was only slightly higher. However, adding an excess of Pt made the nanocomposite films too leaky to exhibit the enhancement. Moreover, the nanocomposite PZT-Pt films in the capacitor configuration of Pt/LaNiO3/PZT-Pt/LaNiO3/Pt also exhibited highly reliable polarization retention and fatigue resistance.