Uniform resistive switching with a thin reactive metal interface layer in metal-La0.7Ca0.3MnO3-metal heterostructures

A thin samarium (Sm) metal layer was introduced to improve the resistive hysteresis and switching uniformity. Sm reacts with the La(0.7)Ca(0.3)MnO(3) and forms a thin interface oxide layer, which is responsible for the switching. The switching occurs without any forming process. Compared with conventional resistive memory device based on localized filament formation, Sm/La(0.7)Ca(0.3)MnO(3) devices show area-dependent resistance which indicates uniform resistive switching. Under a positive bias, electromigration of oxygen ions (O(2-)) forms thicker oxide (SmO(x)), which dissociates under a negative bias, causes high and low resistance states, respectively. Estimated data retention of more than 10 yr was observed at 85 degrees C. (C) 2008 American Institute of Physics.