The influences of doping concentration and element on the resistive switching properties of SZO-based memory devices are investigated in this study. The sputter-deposited LNO bottom electrode and SZO resistive layer exhibit (100)-preferred orientation, and the LNO film annealed at 600 degrees C performs smooth surface and high conductivity. The 0.3% V:SZO memory device depicts the good switching behaviors including high resistance ratio, high endurance, long retention time, and non-destructive readout property. The turn-on voltage is slightly dependent on the SZO thickness, while the turn-off voltage is almost irrelative to the thickness. Besides, the switching properties of MoO3-, MoO2-, and Cr2O3-doped SZO devices are also studied. The results demonstrate that the resistive switching is an intrinsic property of the SZO film, but proper doping concentration and element can improve and stabilize the resistive switching behaviors. (C) 2007 Elsevier B.V. All rights reserved.