Electric Field Induced Sub-Microsecond Resistive Switching

Electric field induced resistive switching in metal-oxide interfaces has attracted extensive recent interest. While many agree that lattice defects play a key role, details of the physical processes are far from clear. There is debate, for example, regarding whether the electromigration of pre-existing point defects or the field-created larger lattice-defects dominates the switch. We investigate several Ag-Pr$_{0.7}$Ca$_{0.3}$MnO$_{3}$ (PCMO) samples exhibiting either sub-microsecond fast switching or slow quasistatic DC switching. It is found that the carrier trapping potentials are very different for the pre-existing point defects associated with doping (and/or electromigration) and the defects responsible for the sub-$\mu $s fast-switching. Creation/removal of the defects with more severe lattice-distortions and spatial spreading (trapping potential $\ge $ 0.35 eV), therefore, should be the dominating mechanism during sub-$\mu $s switching. On the other hand, the shallow defects (trapping potential $<<$ 0.2eV) associated with doping/annealing are most likely responsible for the resistance hysteresis (slow switch) during quasistatic voltage sweep.