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Owing to the advantages of simple structure, low power consumption and high-density integration, memristors or memristive devices are attracting increasing attention in the fields such as next generation non-volatile memories, neuromorphic computation and data encryption. However, the deposition of memristive films often requires expensive equipment, strict vacuum conditions, high energy consumption, and extended processing times. In contrast, electrochemical anodizing can produce metal oxide films quickly (e.g. 10 s) under ambient conditions. By means of the anodizing technique, oxide films, oxide nanotubes, nanowires and nanodots can be fabricated to prepare memristors. Oxide film thickness, nanostructures, defect concentrations, etc, can be varied to regulate device performances by adjusting oxidation parameters such as voltage, current and time. Thus memristors fabricated by the anodic oxidation technique can achieve high device consistency, low variation, and ultrahigh yield rate. This article provides a comprehensive review of the research progress in the field of anodic oxidation assisted fabrication of memristors. Firstly, the principle of anodic oxidation is introduced; then, different types of memristors produced by anodic oxidation and their applications are presented; finally, features and challenges of anodic oxidation for memristor production are elaborated.

Using the calypso algorithm with first-principles calculations, we have predicted two orthorhombic Cmmm and Pmmm structures for YB3. The new structures are energetically much better than the previously proposed WB3-type, ReB3-type, FeB3-type, and TcP3-type structures. We find that the Cmmm phase transforms to the Pmmm phase at about 31 GPa. Subsequent calculations show that the Cmmm phase is mechanical and dynamical stable at ambient conditions. The analysis of the chemical bonding properties indicates that there are strong B–B bonds that make considerable contributions to its stability. [ABSTRACT FROM AUTHOR]

The oxidation behavior and electrical property of a Ni-Mo-Cr alloy at 750°C in a simulated solid oxide fuel cell (SOFC) anode environment (humidified and diluted H2) have been studied. The thermally grown oxide scale presents a multilayered structure, which is similar to that formed in air, with densely grown Cr2O3 in between an underneath layer of the intermetallic compound MoNi3 and a less compact top layer consisting of MnCr2O4 with Cr2O3 flakes embedded. The oxidation kinetics obey a two-stage parabolic law with an initially fast oxidation (0-170 h at a rate of 4.94 X 10-14g2 cm-4 s-1) followed by a slower steady oxidation (170-1000 hat a rate of 2.84 x 10-14 g2 cm-4 s-1). The H2/H2O reducing atmosphere, even with a significantly lower oxygen partial pressure, has a negative effect on the high temperature oxidation resistance; however, it enhances the adherence of the scale to the substrate. The outward diffusion of Ti ions changes the composition, lattice parameters, and diffraction peak positions of the formed oxides, leading to Ti-doped Cr2O3 and the MnCr2O4 spinel. The area specific resistance of the oxide scale preformed at 750°C for 1000 h is 8.34 mΩ cm2 at 750°C, which is higher than that formed in air and lower than that of other studied Ni-based alloys. [ABSTRACT FROM AUTHOR]

As part of an effort to develop robust metallic interconnects for intermediate temperature solid oxide fuel cells, a Ni-Mo-Cr alloy is designed, prepared, and investigated in terms of its microstructure, mechanical property, thermal expansion behavior, oxidation resistance, and electrical property. The developed Ni-Mo-Cr alloy possesses a good thermal expansion compatibility with cell components with a coefficient of thermal expansion smaller than 14 X 10-6/°C at temperature below 800°C. Upon oxidation at 750°C in air, the oxide scale consisted of two kinds of oxide with densely packed and Cr-free NiMn2O4 on top of continuous Cr2O3, and MoNi3 intermetallic compound layer is formed underneath the oxide scale. Two stages of parabolic oxidation kinetics are observed with oxidation rate decrease after 250 h of oxidation, and good thermal cyclicability of the oxide scale is demonstrated. The area-specific resistance (ASR) as a function of oxidation time shows the similar tendency to the oxidation weight gain, giving an ASR at 750°C of 4.48 mΩ cm² for oxidation at 750°C in air for 1000 h and an extrapolated ASR of 22 mΩ cm² for 40,000 h oxidation. [ABSTRACT FROM AUTHOR]

A novel structure of two-dimensional MoS2, with normal and anomalous metallic Ag grating, is proposed to enhance the broadband absorption of monolayer (ML) MoS2 and the photoresponse of MoS2-based photodetectors. The basic physical mechanism of both the normal and anomalous Ag grating with ML MoS2 is understood by studying the magnetic field distribution. The simulation results indicate that magnetic polaritons (MPs) with different orders could form different absorption peaks, and the same-order MPs with different groove heights can also form different absorption peaks, which can meet the expectations of achieving broadband adjustable absorption. Equivalent inductor capacitor circuit theoretical models are adopted to further verify the physical mechanism and resonance conditions of MPs in the structures of normal and anomalous metallic Ag gratings with ML MoS2, demonstrating that the theoretical calculations agree well with the simulation results. The effect of grating geometry for the absorption and photoresponse enhancement of ML MoS2-based photodetectors is also investigated, indicating that anomalous metallic gratings are more effective at achieving broadband absorption and an enhanced photoresponse of ML MoS2 compared with that of normal metallic gratings. [ABSTRACT FROM AUTHOR]

A new phase of RhB4is predicted based on first-principles calculations. The new phase belongs to the orthorhombic Pnnm space group, named as o-RhB4, and analysis of the calculated enthalpy shows that o-RhB4belongs to the orthorhombic Pnnm space group. The calculated phonon band structure shows that the orthorhombic Pnnm o-RhB4structure is stable at ambient pressure. We expect that the phase transition can be further confirmed by experiments. [ABSTRACT FROM AUTHOR]