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We report on the growth and characterization of Ti/La1/3Ca3/2MnO3/SiO2/n-Si memristive devices. We demonstrate that using current as electrical stimulus unveils an intermediate resistance state, in addition to the usual high and low resistance states that are observed in the standard voltage controlled experiments. Based on thorough electrical characterization (impedance spectroscopy, current-voltage curves analysis), we disclose the contribution of three different microscopic regions of the device to the transport properties: an ohmic incomplete metallic filament, a thin manganite layer below the filament tip exhibiting Poole-Frenkel like conduction, and the SiOx layer with an electrical response well characterized by a Child-Langmuir law. Our results suggest that the existence of the SiOx layer plays a key role in the stabilization of the intermediate resistance level, indicating that the combination of two or more active resistive switching oxides adds functionalities in relation to the single-oxide devices. We understand that these multilevel devices are interesting and promising, as their fabrication procedure is rather simple and they are fully compatible with the standard Si-based electronics. [ABSTRACT FROM AUTHOR]

We report on non-volatile memory devices based on multifunctional manganites. The electric field induced resistive switching of Ti/La 1/3 Ca 2/3 MnO 3 / n -Si devices is explored using different measurement protocols. We show that using current as the electrical stimulus (instead of standard voltage-controlled protocols) improves the electrical performance of our devices and unveils an intermediate resistance state. We observe three discrete resistance levels (low, intermediate and high), which can be set either by the application of current–voltage ramps or by means of single pulses. These states exhibit retention and endurance capabilities exceeding 10 4 s and 70 cycles, respectively. We rationalize our experimental observations by proposing a mixed scenario were a metallic filament and a SiO x layer coexist, accounting for the observed resistive switching. Overall electrode area dependence and temperature dependent resistance measurements support our scenario. After device failure takes place, the system can be turned functional again by heating up to low temperature (120 °C), a feature that could be exploited for the design of memristive devices with self-healing functionality. These results give insight into the existence of multiple resistive switching mechanisms in manganite-based memristive systems and provide strategies for controlling them. [ABSTRACT FROM AUTHOR]