Ni-Ti films prepared at 10W and 70W by rf magnetron sputtering are investigated as the oxygen diffusion barrier layer, it is found that crystallinity of Ni-Ti film does not greatly depend on the deposition power. X-ray photoelectron spectroscopy indicates that Ni is still in the form of metallic state from the binding energies of both Ni 2p(3/2) and Ni 2p(1/2) spectra for the sample with 10W prepared Ni-Ti, however, Ni is oxidized for 70W prepared Ni-Ti film. Moreover, the (La0.5Sr0.5)CoO3/Pb(Zr0.40Ti0.60)O-3/(La0.5Sr0.5)CoO3 capacitor grown on high power prepared Ni-Ti film is leaky, however, the capacitor on low power prepared Ni-Ti film possesses very promising physical properties (i.e. remnant polarization of similar to 27 mu C/cm(2) at 5 V and maximum dielectric constant of 940). Leakage current density of the capacitor grown on low power prepared Ni-Ti film is further investigated, it meets ohmic behavior (<1.0 V) and agrees well with the space-charge-limited current theory (>1.0 V). (C) 2009 Elsevier B. V. All rights reserved.