Niobium-doped (Pb0.8Ba0.2)ZrO3 (PBNZ) thin films were prepared by RF-magnetron sputtering at room temperature followed by postannealing at 700degreesC. The doping concentration of Nb is in the range from 0 up to 2.5 at%. The introduction of Nb enhances the ferroelectric property and suppresses the leakage Current of the PBNZ films. A large remanent polarization (P-r) of 2P(r) = 35 muC/cm(2) can be obtained from a doping of 1.5 at% Nb in the PBNZ film in comparison to that of 19 muC/cm(2) from the undoped PBZ film. The Pt/PBNZ/Pt capacitor also exhibits a high fatigue resistance against polarization switching tip to 10(10) cycle as that of Pt/PBZ/Pt. Moreover, an improvement of retention property can be also achieved from Nb doping. (C) 2004 Elsevier B.V. All rights reserved.