Nature Of Resistive Switching Research Articles

Giant spin-valve effect in yttrium--ion garnet--aluminum structures

The nature of resistive switching in structures of yttrium iron garnet-aluminum (YIG/Al) observed when the current direction is changed relative to the direction of YIG magnetization has been studied. It has been established that the effect observed when the magnetic field is rotated increases with an increase in the current passed through the structure and achieves 100 percent switching from the superconducting to the normal resistive state. The magnitude of the effect depends on geometric factors, namely, on the ratio of the lateral dimensions of the YIG plates. Modeling the configuration of the magnetostatic stray fields showed that the effect is partially determined by these fields. It has been established that the inversion of the current flowing through the structures also leads to a variation in their resistance. The effect reaches 20% near the temperature of superconducting transition. Keywords: magnetic dielectrics, superconductor, proximity effects, spin-orbit coupling, Zeeman field, spin-valve.

Correlation analysis between the current fluctuation characteristics and the conductive filament morphology of HfO2-based memristor

Memristors are attracting considerable interest for their prospective applications in nonvolatile memory, neuromorphic computing, and in-memory computing. However, the nature of resistance switching is still under debate, and current fluctuation in memristors is one of the critical concerns for stable performance. In this work, random telegraph noise (RTN) as the indication of current instabilities in distinct resistance states of the Pt/Ti/HfO2/W memristor is thoroughly investigated. Standard two-level digital-like RTN, multilevel current instabilities with non-correlation/correlation defects, and irreversible current transitions are observed and analyzed. The dependence of RTN on the resistance and read bias reveals that the current fluctuation depends strongly on the morphology and evolution of the conductive filament composed of oxygen vacancies. Our results link the current fluctuation behaviors to the evolution of the conductive filament and will guide continuous optimization of memristive devices.

Random telegraph noise and resistance switching analysis of oxide based resistive memory

Resistive random access memory (RRAM) devices (e.g."memristors") are widely believed to be a promising candidate for future memory and logic applications. Although excellent performance has been reported, the nature of resistance switching is still under extensive debate. In this study, we perform systematic investigation of the resistance switching mechanism in a TaOx based RRAM through detailed noise analysis, and show that the resistance switching from high-resistance to low-resistance is accompanied by a semiconductor-to-metal transition mediated by the accumulation of oxygen-vacancies in the conduction path. Specifically, pronounced random-telegraph noise (RTN) with values up to 25% was observed in the device high-resistance state (HRS) but not in the low-resistance state (LRS). Through time-domain and temperature dependent analysis, we show that the RTN effect shares the same origin as the resistive switching effects, and both can be traced to the (re)distribution of oxygen vacancies (VOs). From noise and transport analysis we further obtained the density of states and average distance of the VOs at different resistance states, and developed a unified model to explain the conduction in both the HRS and the LRS and account for the resistance switching effects in these devices. Significantly, it was found that even though the conduction channel area is larger in the HRS, during resistive switching a localized region gains significantly higher VO and dominates the conduction process. These findings reveal the complex dynamics involved during resistive switching and will help guide continued optimization in the design and operation of this important emerging device class.