Observation of a Large Slip Effect in the Nanoscale Flow of Highly Viscous Supercooled Liquid Metals.

Understanding and controlling the flow of materials confined in channels play important roles in science and engineering. The general no-slip boundary condition will result in it being more challenging to drive the flow as the channel size decreases to the nanoscale, especially for highly viscous liquids. Here, we report the observation of a large boundary slip in the nanoscale flow of highly viscous supercooled liquid metals (with viscosities of ≲10 Pa s), enabled by the hydrophobic treatment of smooth nanochannels.

Light-Programmed Bistate Colloidal Actuation Based on Photothermal Active Plasmonic Substrate.

Active particles have been regarded as the key models to mimic and understand the complex systems of nature. Although chemical and field-powered active particles have received wide attentions, light-programmed actuation with long-range interaction and high throughput remains elusive. Here, we utilize photothermal active plasmonic substrate made of porous anodic aluminum oxide filled with Au nanoparticles and poly(-isopropylacrylamide) (PNIPAM) to optically oscillate silica beads with robust reversibility.

Observation of enhanced nanoscale creep flow of crystalline metals enabled by controlling surface wettability.

Understanding and controlling interface friction are central to many science and engineering applications. However, frictional sliding is closely related to adhesion, surface roughness, surface chemistry, mechanical deformation of contact solids, which poses the major challenge to experimental studying and theoretical modeling of friction. Here, by exploiting the recent developed thermomechanical nanomolding technique, we present a simple strategy to decouple the interplay between surface chemistry, plastic deformation, and interface friction by monitoring the nanoscale creep flow of metals in nanochannels.

Synthesis of stable γ-phase MnSSe nanoflakes with inversion symmetry breaking.

Inversion symmetry breaking plays a critical role in the formation of magnetic skyrmions. Therefore, for the application of skyrmion-based devices, it is important to develop novel engineering techniques and explore new non-centrosymmetric lattices. In this paper, we report the rational synthesis of stable γ-phase MnSSe (0 ≤ ≤ 0.

Optically Triggered Nanoscale Plasmonic Dynamite.

Photons as energy carriers are clean and abundant, which can be conveniently applied for nanoactuation but the response is usually slow with very low energy efficiency/density. Here, we underpin the concept of robust nanoscale plasmonic dynamite by incorporating fullerene (C). The Au@C core-shell nanoparticles can be triggered to explode in nanoscale with synergy of plasmon-enhanced photochemical and photothermal effects.

Electrochemical Growth of High-Strength Carbon Nanocoils in Molten Carbonates.

The reported mechanical strength of carbon nanocoils (CNCs) obtained from traditional preparation of catalytic acetylene pyrolysis is far below its theoretical value. Herein, we report a molten salt electrolysis method that employs CO as feedstock to grow CNCs without using metal catalyst. We meticulously mediate the alkalinity of molten carbonate to tune the electrochemical reduction of CO on graphite electrode to selectively grow CNCs in LiCO-NaCO-KCO-0.

Nanomolding of Gold and Gold-Silicon Heterostructures at Room Temperature.

Nanofabrication techniques are limited by at least one of the required characteristics such as choice of material, control over geometry, fabrication requirements, yield, cost, and scalability. Our previously developed method of thermomechanical nanomolding fulfills these requirements, although it requires high processing temperatures. Here, we demonstrate low-temperature molding where we utilize the enhanced diffusivity on "eutectic interfaces".

Colossal Anomalous Hall Effect in Ferromagnetic van der Waals CrTe.

van der Waals crystals exhibit excellent material performance when exfoliated to few-atomic-layer thickness. In contrast, the van der Waals thin films more than 10 nm thick are believed to show bulk properties, in which outstanding material performance is rarely found. Here we report the largest anomalous Hall conductivity observed so far in a 170 nm van der Waals ferromagnetic 1-CrTe flake, which reaches 67,000 Ω cm.

A Biaxial Strain Sensor Using a Single MoS Grating.

In this paper, we report a new type of MoS-based grating sensor for in-plane biaxial strain gauges with a precision limit of ~ 1‰. The MoS grating is numerically simulated with different biaxial strains up to 5%. Our first-principles calculations reveal that the strain sensitivity of the MoS reflectance spectrum can be considered an additional strain sensor integrated with the grating structure, enabling the mapping of in-plane biaxial strains.

Antisymmetric Magnetoresistance in a van der Waals Antiferromagnetic/Ferromagnetic Layered MnPS/FeGeTe Stacking Heterostructure.

The presence of two-dimensional (2D) layer-stacking heterostructures that can efficiently tune the interface properties by stacking desirable materials provides a platform to investigate some physical phenomena, such as the proximity effect and magnetic exchange coupling. Here, we report the observation of antisymmetric magnetoresistance in a van der Waals (vdW) antiferromagnetic/ferromagnetic (AFM/FM) heterostructure of MnPS/FeGeTe when the temperature is below the Neel temperature of MnPS. Distinguished from two resistance states in conventional giant magnetoresistance, the magnetoresistance in the MnPS/FeGeTe heterostructure exhibits three states, of high, intermediate, and low resistance.

Birefringence-like spin transport via linearly polarized antiferromagnetic magnons.

Antiferromagnets (AFMs) possess great potential in spintronics because of their immunity to external magnetic disturbance, the absence of a stray field or the resonance in the terahertz range. The coupling of insulating AFMs to spin-orbit materials enables spin transport via AFM magnons. In particular, spin transmission over several micrometres occurs in some AFMs with easy-axis anisotropy.

Sn-Stabilization in MASnI perovskites by superhalide incorporation.

Sn-based hybrid halide perovskites are a potential solution to replace Pb and thereby reduce Pb toxicity in MAPbI perovskite-based solar cells. However, the instability of Sn in air atmosphere causes a poor reproducibility of MASnI, hindering steps towards this goal. In this paper, we propose a new type of organic metal-superhalide perovskite of MASnIBH and MASnIAlH.

Tunable photoluminescence of MoS quantum dots passivated by different functional groups.

Recently, transitional metal dichalcogenides quantum dots have attracted much interest as a potential candidate for the application of fluorescent materials. However, little work has been done on tuning their band gap by varying functional groups. Here, we report a band-gap tunability of 1eV in the MoS quantum dots (QDs) modified by different functional groups.