Electric-field-induced submicrosecond 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-Pr0.7 Ca0.3 MnO3 samples exhibiting either submicrosecond 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 for the defects responsible for the submicrosecond fast switching. Creation/removal of the defects with more severe lattice distortions and spatial spreading (trapping potential ≥0.35 eV), therefore, should be the dominating mechanism during submicrosecond switching. On the other hand, the shallow defects (trapping potential ≪0.2 eV) associated with doping/annealing are most likely responsible for the resistance hysteresis (slow switch) during quasistatic voltage sweep.