Abstract Tunneling measurements at different temperatures were carried out in SrRuO 3 /Pb(Zr 0.52 Ti 0.48 )O 3 /Pt capacitor structures grown on (100) SrTiO 3 single‐crystal substrates using a high‐oxygen pressure on axis sputtering technique. Crystalline quality and structure were measured by X‐ray diffractometry (XRD). The surface roughness and morphology were studied by atomic force microscopy (AFM). Electrical characterization was carried out by P – E hysteresis loops and fatigue measurements on different capacitors. Capacitor structures with electrode areas of 5.0 × 10 –4 and 6.5 × 10 –3 cm 2 revealed remanent polarizations around of 30 µC/cm 2 at room temperature. Current–voltage characteristics ( I – V curves) demonstrated slight hysteretic behavior while the bias voltage dependence of the dynamic conductance measurements presented a parabolic characteristic, indicating electron tunneling. A Brinkman fit of the normalized conductance curves as a function of temperature gives barrier thicknesses below 2 nm. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)