Growth and self-assembly of BaTiO3 nanocubes for resistive switching memory cells

Ultra-high resistive switching current ratio and improved ferroelectricity and dielectric tunability performance in a BaTiO3/La0.7Sr0.3MnO3 heterostructure by inserting a SrCoO2.5 layer

A BaTiO3/SrCoO2.5 (BTO/SCO) bilayer and a BTO single film were prepared by radio frequency magnetron sputtering on La0.7Sr0.3MnO3 (LSMO) buffered SrTiO3 (001) substrates. Interestingly, compared with reported BTO-based films, the BTO/SCO/LSMO heterostructure has a maximum ON/OFF current ratio of ∼945. More interestingly, compared with the BTO single layer, a larger Pr (∼18.4 μC cm-2) and larger dielectric tunability (∼71.9%) were achieved in the BTO/SCO bilayer. The improved performance may be attributed to the large tetragonality and improved oxygen vacancy concentrations in the BTO/SCO/LSMO heterostructure. Furthermore, our BTO/SCO/LSMO stacks exhibit potential for flexible electronic informational devices.

Resistive random access memory: introduction to device mechanism, materials and application to neuromorphic computing

The modern-day computing technologies are continuously undergoing a rapid changing landscape; thus, the demands of new memory types are growing that will be fast, energy efficient and durable. The limited scaling capabilities of the conventional memory technologies are pushing the limits of data-intense applications beyond the scope of silicon-based complementary metal oxide semiconductors (CMOS). Resistive random access memory (RRAM) is one of the most suitable emerging memory technologies candidates that have demonstrated potential to replace state-of-the-art integrated electronic devices for advanced computing and digital and analog circuit applications including neuromorphic networks. RRAM has grown in prominence in the recent years due to its simple structure, long retention, high operating speed, ultra-low-power operation capabilities, ability to scale to lower dimensions without affecting the device performance and the possibility of three-dimensional integration for high-density applications. Over the past few years, research has shown RRAM as one of the most suitable candidates for designing efficient, intelligent and secure computing system in the post-CMOS era. In this manuscript, the journey and the device engineering of RRAM with a special focus on the resistive switching mechanism are detailed. This review also focuses on the RRAM based on two-dimensional (2D) materials, as 2D materials offer unique electrical, chemical, mechanical and physical properties owing to their ultrathin, flexible and multilayer structure. Finally, the applications of RRAM in the field of neuromorphic computing are presented.

Bipolar resistive switching with negative differential resistance effect in a Cu/BaTiO3/Ag device

We demonstrate that a bipolar non-volatile resistive switching behaviour with negative differential resistance (NDR) effect is realized in a Cu/BaTiO₃/Ag device, which was deposited on a Si substrate via magnetron sputtering equipment. We suggest that the bipolar resistive switching is dominated by the trapping/detrapping of electrons at the BaTiO₃-Cu interface. In addition, we demonstrate that the device exhibits good performance, including a large on/off ratio, high reliability and long retention time. Therefore, BaTiO₃ may become a good candidate for application in resistive switching random access memory (RRAM) devices.

Resistive Switching of Sub-10 nm TiO₂ Nanoparticle Self-Assembled Monolayers

Resistively switching devices are promising candidates for the next generation of non-volatile data memories. Such devices are up to now fabricated mainly by means of top-down approaches that apply thin films sandwiched between electrodes. Recent works have demonstrated that resistive switching (RS) is also feasible on chemically synthesized nanoparticles (NPs) in the 50 nm range. Following this concept, we developed this approach further to the sub-10 nm range. In this work, we report RS of sub-10 nm TiO₂ NPs that were self-assembled into monolayers and transferred onto metallic substrates. We electrically characterized these monolayers in regard to their RS properties by means of a nanorobotics system in a scanning electron microscope, and found features typical of bipolar resistive switching.

Switchable self-assembly of Prussian blue analogs nano-tiles triggered by salt stimulus

We showed fully reversible, ionic strength controlled self-assembly of Prussian blue analogues nano-tiles into large superlattice structures.