Articles you may be interested inPiezoresponse force microscopy studies on the domain structures and local switching behavior of Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 single crystals

Switching of the out-of-plane and in-plane polarizations in polydomain epitaxial PbZr 0.2 Ti 0.8 O 3 thin films is studied using three-dimensional piezoresponse force microscopy ͑PFM͒. It is found that, under an electric field induced between the PFM tip and the bottom electrode, the 180°switching occurs in both c and a domains. After the removal of this field, the spontaneous reversal of the out-of-plane and in-plane polarizations back to the initial orientations takes place, evolving via heterogeneous development of antiparallel 180°domains. The switching of in-plane polarization inside a domains and the preferential formation of reversed 180°domains at 90°domain walls are explained by the effects of the depolarizing fields caused by transient polarization charges appearing on these domain walls.

We report on a novel approach for the investigation of the Pb(ZrxTi1−x)O3/Pt interface applying scanning force microscopy techniques. Ferroelectric samples (PZT film /Pt/SiO2/Si) were polished at a shallow angle (∼6.1°) thereby enlarging the film cross section from a 430 nm film thickness to a width of more than 4 μm. Piezoresponse force microscopy and Kelvin probe force microscopy were applied in order to deduce the dielectric polarization P and local potential distribution over the full cross section. We clearly observe a transition layer with a thickness of ∼240 nm which manifests itself both in a gradual decrease of the piezoresponse signal as a function of film thickness and in a corresponding variation of the surface potential. Furthermore, after polarization reversal due to a dc voltage applied to the tip, a different retention behavior was observed within the transition layer. The results are tentatively attributed to negatively charged defects accumulated at the PZT/Pt interface.

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