Direct hysteresis measurements of single nanosized ferroelectric capacitors contacted with an atomic force microscope

Direct hysteresis measurements on single submicron structure sizes were per formed on epitaxial ferroelectric Pb(Zr,Ti)O-3 thin films grown on SrTiO3 w ith La0.5Sr0.5CoO3 (LSCO) electrodes. The samples were fabricated by focuse d-ion-beam milling resulting in pad sizes down to 200 nmx200 nm. The influe nce of parasitic capacitance of the measurement setup was eliminated by app lying an enhanced compensation procedure. No size effects were observed in capacitors milled down to 400 nmx400 nm. Thus, a published increase of P-ma x(1) for decreasing pad size can be explained by the parasitic influence of the setup. Finally, the inaccuracy of increasing coercive voltage due to t he coating of the cantilever of the atomic force microscope is discussed. ( C) 2001 American Institute of Physics.