Figure 4.

aImpedance spectra of the NBT memory device are represented by dashed lines. Impedance spectra simulated are represented bysolid lines,and the corresponding equivalent circuit models are shown in the insert.bFrequency dependence of the impedance spectra in the on state and off state.Solidsymbols correspond to the high-resistance states andopensymbols correspond to low-resistance states

Zhang et al. Nanoscale Research Letters 2009 4:1309-1314   doi:10.1007/s11671-009-9397-4