Bipolar Resistive Behavior Research Articles

Exchange bias coupling and bipolar resistive switching at room temperature on GaSb/Mn multilayers for resistive memories applications

This work present structural, morphological, magnetic, and electrical properties of GaSb/Mn multilayer deposited via DC magnetron sputtering at room temperature and at 423 K. The samples are characterized by forming layers of 3, 6 and 12 periods of the GaSb/Mn structure. Through XRD patterns, it was possible to stablish the formation of GaSb, Mn3Ga, and Mn2Sb2 phases. FTIR measurements present an optical interference associated with periodicity and the homogenous thickness of the layers. HR-SEM shows the multilayer architecture with columnar microstructure in the formation of layers with grain nucleation on the surface. A ferromagnetic-like behavior was observed in the multilayers at room temperature related to the domains and interlayers interaction. Additionally, the hysteresis curves present shifts attributed to the effect of exchange bias coupling. I-V curves show RESET-SET states of the multilayer system with bipolar resistive behavior, which can be modified by external magnetic fields. The resistive switching evidenced corresponds to the conductive mechanism based on the capacitive conductance and the formation of conductive filaments in multilayer structure.

Characteristics of the bipolar resistive switching behavior in memory device with Au/ZnO/ITO structure

In this work, reproducible and stable bipolar resistive switching behavior without the requirement of forming process is observed in the memory device with Au/ZnO/ITO structure. It shows a high Ron/Roff ratio, where Ron and Roff are the resistance at low resistance state (LRS) and high resistance state (HRS), respectively. The dominated transport mechanisms for LRS and HRS are related to space charge limited current and Ohmic behavior, respectively. This bipolar resistive behavior is attributed to the formation and rupture of conducting filaments which are constructed with oxygen vacancies. The Au/ZnO/ITO device discussed in this work shows huge potential applications in the next generation nonvolatile memory field.

Effects of Annealing Temperature on Resistance Switching Properties of ZnMn<sub>2</sub>O<sub>4</sub> Films Deposited by Magnetron Sputtering

ZnMn2O4films were fabricated on p-Si substrate by magnetron sputtering. The effects of annealing temperature on microstructure, resistance switching properties and endurance characteristics of ZnMn2O4films were investigated. The ZnMn2O4films with a structure of Ag/ZnMn2O4/p-Si exhibit bipolar resistive switching behavior. The results indicated that the annealing temperature has not changed its spinel structure, the bipolar resistance behavior and endurance characteristics, but the grain become more and more large, arranged closed and distributed evenly with the increase of annealing temperature from 450°C to 750°C. The ZnMn2O4films annealed at 600°C have the biggestRHRS/RLRSratio, the lowestVONandVOFF. TheRHRS/RLRSratios of all specimens maintain at about 103after successive 1000 switching cycles, which indicated that the Ag/ZnMn2O4/p-Si device has better endurance characteristics.