Resistive switching memory performance in oxide hetero-nanocrystals with well-controlled interfaces

Abstract

For realization of new informative systems, the memristor working like synapse has drawn much attention. We developed isolated high-density Fe 3 O 4 nanocrystals on Ge nuclei/Si with uniform and high resistive switching performance using low-temperature growth. The Fe 3 O 4 nanocrystals on Ge nuclei had a well-controlled interface (Fe 3 O 4 /GeO x /Ge) composed of highcrystallinity Fe 3 O 4 and high-quality GeO x layers. The nanocrystals showed uniform resistive switching characteristics (high switching probability of~90%) and relatively high Off/On resistance ratio (~58). The high-quality interface enables electric field application to Fe 3 O 4 and GeO x near the interface, which leads to effective positively charged oxygen vacancy movement, resulting in high-performance resistive switching. Furthermore, we successfully observed memory effect in nanocrystals with well-controlled interface. The experimental confirmation of the memory effect existence even in ultrasmall nanocrystals is significant for realizing non-volatile nanocrystal memory leading to neuromorphic devices.

High‐Uniformity Threshold Switching HfO2‐Based Selectors with Patterned Ag Nanodots

“…However, the HfO x :N selectors show unidirectional switching characteristics, and also slow speed with typical switching time longer than 1.5 µs. Some previous works have reported that the device characteristics of RRAM can be improved by using NDs, [40][41][42][43] such as ordered metal/oxide/metal NDs and Ag 2 S/Ag NDs for nanoscale RRAM. In our previous study, an ultrathin anodic aluminum oxide (AAO) template was used as a pattern mask to fabricate Ag NDs as the active metal source in the selector.…”

Properties of self-oxidized single crystalline perovskite N : BaTiO3 oxynitride epitaxial thin films

“…The widths of the diffraction peaks of SrTiO 3 (001) are limited by the instrumental contribution and are thus very sharp and point out the high crystalline quality of the single crystalline substrate. The specular Bragg peaks of N:BTO appear in the form of broad peaks on the low L side of the Nb:SrTiO 3 Bragg peaks and contain information about the film thickness and strain [23][24][25][26] . Epitaxial single crystalline films only exhibit a single family of Bragg peaks along (00L) limiting the number of peaks that can be taken into account in a structural size-strain nanoparticle analysis 27 .…”

Phonon transport in the nano-system of Si and SiGe films with Ge nanodots and approach to ultralow thermal conductivity

“…We have developed the formation technique of well-controlled nanostructures in the films, such as epitaxial NDs with several nm to tens of nm in size. 12,13,17,26,[28][29][30][33][34][35][36][37] Our connected Si NDs exhibited extremely-low thermal conductivity, κ (∼0.78 W m −1 K −1 ) 12 compared with other crystal Si materials. Thanks to the well-controlled nanostructured interfaces, it was revealed that this ultralow κ value was brought by confinement of phonon propagation close to the Cahill-Pohl limit.…”