Method to distinguish ferroelectric from nonferroelectric origin in case of resistive switching in ferroelectric capacitors

We present investigations on the resistive switching effect in SrRuO3/PbZr0.2Ti0.8O3/Pt ferroelectric capacitors. Using a conductive atomic force microscope, the out-of-plane piezoelectric response and the capacitive and resistive current were simultaneously measured as a function of applied bias voltage. We observed two independent switching phenomena, one attributed to the ferroelectric switching process and the other to resistive switching. We show that I-V curves alone are not sufficient in ferroelectric materials to clarify the underlying switching mechanism and must be used with sufficient caution. (C) 2008 American Institute of Physics

Improved PbZr0.52Ti0.48O3 film quality on SrRuO3/SrTiO3 substrates

We have used high-pressure on-axis sputtering to deposit single crystalline epitaxial PbZr0.52Ti0.48O3 either on SrRuO3/SrTiO3 or on SrTiO3 substrates. The PbZr0.52Ti0.48O3 films possess a small mosaicity on both, on SrRuO3/SrTiO3 and on SrTiO3 substrates. PbZr0.52Ti0.48O3 thin films have a larger out-of-plane lattice parameter and a smaller in-plane lattice parameter when it is grown on SrRuO3/SrTiO3 substrates. Atomic force microscopy reveals very smooth surfaces. The stoichiometry has been verified by Rutherford backscattering spectrometry. Channeling measurements indicate that the crystalline quality of the PbZr0.52Ti0.48O3 films grown on SrRuO3/SrTiO3 substrate is significantly improved compared to its deposition on blank SrTiO3 substrates. This observation is discussed in the framework of lattice mismatch, thermal expansion coefficients, interdiffusion at the PbZr0.52Ti0.48O3/SrRuO3 interface, the depolarization field in the ferroelectrics and the surface layer termination of the substrate. (c) 2005 Elsevier B.V. All rights reserved