SPM studies on surface charge and local piezo-response of ferroelectric thin films

Ferroelectric (Ba0.67Sr0.33)TiO3 and Pb(Zr0.53Ti0.47)O-3 thin films have been prepared by the RF magnetron sputtering process, and characterized using scanning probe microscopy. Two distinct grain-boundary space charge regions are observed in the BST films by the contact KPFM. Such charged grain-boundaries are correlated to their leakage current behaviors. The ferroelectric domain and retention properties of the PZT 53/47 thin films are also investigated using EFM. The time dependence of the remnant polarization is identified to follow a stretched exponential decay.