Resistive memory switching in layered oxides: AnBnO3n+2 perovskite derivatives and Bi2Sr2CaCu2O8+d high-Tc superconductor
Physica Status Solidi (a) 208(2): 284-299
Abstract Resistive memory switching was investigated in titanates and niobates of the type AnBnO3n+2 and in the high-Tc superconductor Bi2Sr2CaCu2O8+d. We studied the switching by current injection perpendicular to the layers. Both dc and pulsed measurements were performed. Out-of-plane transport properties were investigated by measurements of the resistance and currentvoltage characteristics (IVs) vs. temperature for different resistive states. The critical temperature of superconducting transition and the critical current of intrinsic Josephson junctions were also analyzed for different resistive states in Bi2Sr2CaCu2O8+d. The resistive memory switching was explained in terms of doping of the conducting layers, which is induced by trapped charges in the insulating layers. The charged insulating layers act as a floating gate and reduce or increase the carrier concentration in the conducting layers, respectively. We found that all studied materials demonstrate a different type of non-persistent resistive switching at low temperatures. This type of switching shows up in a specific form of currentvoltage characteristics with a pronounced back-bending often called s-shaped IV. Both types of resistive switching with and without memory effect were analyzed in terms of electron overheating. We examine the role of hot electrons and discuss additional factors, which might lead to persistent resistive states.