Impedance spectroscopy of TiO2 thin films showing resistive switching

Impedance characteristics of 27 nm thick anatase TiO2 films showing bistable resistive switching were investigated in the frequency domain (100 Hz-10 MHz) in various resistance states, a fresh state (before electroforming), a high resistive state (HRS), and a low resistive state (LRS). dc conductance in the film becomes dominent in HRS and LRS and the capacitances in the various states are almost identical. Numerical calculations using finite element analysis were performed for the localized filament and homogeneous model, whose results suggest that the filament model is consistent with the experimental results. (c) 2006 American Institute of Physics.