Uniform resistive switching with a thin reactive metal interface layer in metal- La0.7 Ca0.3 Mn O3 -metal heterostructures

Abstract

A thin samarium (Sm) metal layer was introduced to improve the resistive hysteresis and switching uniformity. Sm reacts with the La0.7 Ca 0.3 Mn O3 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 La0.7 Ca0.3 Mn O3 devices show area-dependent resistance which indicates uniform resistive switching. Under a positive bias, electromigration of oxygen ions (O2-) forms thicker oxide (Sm Ox), 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 °C. © 2008 American Institute of Physics.