Engineering Interlayer Electron-Phonon Coupling in WS/BN Heterostructures.

In van der Waals (vdW) heterostructures, the interlayer electron-phonon coupling (EPC) provides one unique channel to nonlocally engineer these elementary particles. However, limited by the stringent occurrence conditions, the efficient engineering of interlayer EPC remains elusive. Here we report a multitier engineering of interlayer EPC in WS/boron nitride (BN) heterostructures, including isotope enrichments of BN substrates, temperature, and high-pressure tuning.

Air-Stable Monolayer Cu Se Exhibits a Purely Thermal Structural Phase Transition.

Materials possessing structural phase transformations exhibit a rich set of physical and chemical properties that can be used for a variety of applications. In 2D materials, structural transformations have so far been induced by strain, lasers, electron injection, electron/ion beams, thermal loss of stoichiometry, and chemical treatments or by a combination of such approaches and annealing. However, stoichiometry-preserving, purely thermal, reversible phase transitions, which are fundamental in physics and can be easily induced, have not been observed.

Observation of the Kondo Effect in Multilayer Single-Crystalline VTe Nanoplates.

We report the chemical vapor deposition (CVD) growth, characterization, and low-temperature magnetotransport of 1T phase multilayer single-crystalline VTe nanoplates. The transport studies reveal that no sign of intrinsic long-range ferromagnetism but localized magnetic moments exist in the individual multilayer metallic VTe nanoplates. The localized moments give rise to the Kondo effect, evidenced by logarithmical increment of resistivity with decreasing temperature and negative magnetoresistance (NMR) regardless of the direction of magnetic field at temperatures below the resistivity minimum.

Carbon nanofiber interlayer: a highly effective strategy to stabilize silicon anodes for use in lithium-ion batteries.

Silicon (Si) possesses the highest theoretical capacity as an anode material for lithium-ion batteries, and many efforts have been made to address the poor cycling stability issue that is associated with its huge volume changes during Li-Si alloying/de-alloying processes, mostly through the design of nanostructured materials. Herein, we report a simple cell configuration approach to improve the lithium storage performance of commercial nano-Si through the insertion of carbon nanofiber films (CNFs) as interlayers between the Si electrodes and separators. For this advanced cell configuration, commercial Si nanoparticle (Si NP) electrodes demonstrate a significantly improved reversible capacity (2700 mA h g-1 after 40 cycles at 50 mA g-1) and an ultralong cycle life (1250 mA h g-1 after 430 cycles at 1500 mA g-1).

Temporary formation of highly conducting domain walls for non-destructive read-out of ferroelectric domain-wall resistance switching memories.

Erasable conductive domain walls in insulating ferroelectric thin films can be used for non-destructive electrical read-out of the polarization states in ferroelectric memories. Still, the domain-wall currents extracted by these devices have not yet reached the intensity and stability required to drive read-out circuits operating at high speeds. This study demonstrated non-destructive read-out of digital data stored using specific domain-wall configurations in epitaxial BiFeO thin films formed in mesa-geometry structures.

Wafer-Scale Growth and Transfer of Highly-Oriented Monolayer MoS Continuous Films.

Large scale epitaxial growth and transfer of monolayer MoS has attracted great attention in recent years. Here, we report the wafer-scale epitaxial growth of highly oriented continuous and uniform monolayer MoS films on single-crystalline sapphire wafers by chemical vapor deposition (CVD) method. The epitaxial film is of high quality and stitched by many 0°, 60° domains and 60°-domain boundaries.

In Situ Atomic-Scale Observation of Electrochemical Delithiation Induced Structure Evolution of LiCoO Cathode in a Working All-Solid-State Battery.

We report a method for in situ atomic-scale observation of electrochemical delithiation in a working all-solid-state battery using a state-of-the-art chip based in situ transmission electron microscopy (TEM) holder and focused ion beam milling to prepare an all-solid-state lithium-ion battery sample. A battery consisting of LiCoO cathode, LLZO solid state electrolyte and gold anode was constructed, delithiated and observed in an aberration corrected scanning transmission electron microscope at atomic scale. We found that the pristine single crystal LiCoO became nanosized polycrystal connected by coherent twin boundaries and antiphase domain boundaries after high voltage delithiation.

A room-temperature magnetic semiconductor from a ferromagnetic metallic glass.

Emerging for future spintronic/electronic applications, magnetic semiconductors have stimulated intense interest due to their promises for new functionalities and device concepts. So far, the so-called diluted magnetic semiconductors attract many attentions, yet it remains challenging to increase their Curie temperatures above room temperature, particularly those based on III-V semiconductors. In contrast to the concept of doping magnetic elements into conventional semiconductors to make diluted magnetic semiconductors, here we propose to oxidize originally ferromagnetic metals/alloys to form new species of magnetic semiconductors.

FeS@C on Carbon Cloth as Flexible Electrode for Both Lithium and Sodium Storage.

Flexible and self-supported carbon-coated FeS on carbon cloth films (denoted as FeS@C/carbon cloth) is prepared by a facial hydrothermal method combined with a carbonization treatment. The FeS@C/carbon cloth could be directly used as electrodes for Li-ion batteries (LIBs) and sodium-ion batteries (NIBs). The synthetic effects of the structure, highly electron-conductive of carbon cloth, porous structure for electrolyte access, and uniform carbon shell on FeS surface to accommodate the volume change lead to improved cyclability and rate capability.

Longitudinal wave function control in single quantum dots with an applied magnetic field.

Controlling single-particle wave functions in single semiconductor quantum dots is in demand to implement solid-state quantum information processing and spintronics. Normally, particle wave functions can be tuned transversely by an perpendicular magnetic field. We report a longitudinal wave function control in single quantum dots with a magnetic field.

A new non-destructive readout by using photo-recovered surface potential contrast.

Ferroelectric random access memory is still challenging in the feature of combination of room temperature stability, non-destructive readout and high intensity storage. As a non-contact and non-destructive information readout method, surface potential has never been paid enough attention because of the unavoidable decay of the surface potential contrast between oppositely polarized domains. That is mainly due to the recombination of the surface movable charges around the domain walls.