Surface Reconstruction and Layer-Dependent Semiconductor-to-Metal Transition of Zinc-Blende CdSe.

In this work, CdSe was taken as the representation to systematically investigate the (111) and (110) surface reconstructions, the electronic properties transition related to the layer size, and the corresponding physical mechanism through the density functional theory (DFT) calculation. For the (111) surface slab structure, the bulk truncated relaxation (BTR) surface and the honeycomb (HC) surface were carefully examined. The HC surface configuration, ignored by previous studies, is an energetically preferred surface compared to both the as-truncated and BTR configurations.

Out-of-plane pressure and electron doping inducing phase and magnetic transitions in GeC/CrS/GeC van der Waals heterostructure.

Out-of-plane pressure and electron doping can affect interlayer interactions in van der Waals materials, modifying their crystal structure and physical and chemical properties. In this study, we used magnetic monolayer 1T/1T'-CrS and high symmetry 2D-honeycomb material GeC to construct a GeC/CrS/GeC triple layered van der Waals heterostructure (vdWH). Based on density functional theory calculations, we found that applying out-of-plane strain and doping with electrons could induce a 1T'-to-1T phase transition and consequently the ferromagnetic (FM)-to-antiferromagnetic (AFM) transition in the CrS layer.

Superior Thermal Conductivity of Graphene Film/Cu-Zr Alloy Composites for Thermal Management Applications.

As the power density of electronic devices continuously increases, there is a growing demand to improve the heat conduction performance of thermal management materials for addressing heat dissipation issues. Single-/few-layer graphene is a promising candidate as a filler of a metal matrix due to its extremely high thermal conductivity (); however, the well-arranged assembly of 2D-component graphene with a high volume fraction remains challenging. Herein, we integrated a novel graphene-based macroscopic material of graphene film (GF) into a Cu matrix by infiltrating molten Zr-microalloyed Cu into a spirally folded and upright-standing GFs skeleton.

Designing of Efficient Bifunctional ORR/OER Pt Single-Atom Catalysts Based on O-Terminated MXenes by First-Principles Calculations.

MXenes have been used as substrate materials for single-atom catalysts (SACs) due to their unique two-dimensional (2D) structure, high surface area, and high electronic conductivity. Oxygen is the primary terminating group of MXenes; however, all of the reported Pt SACs till now are fabricated with F-terminated MXenes. According to the first-principles calculations of this work, the failure of using O-terminated MXenes as substrates is due to the low charge density around Pt and C, which weakens the catalytic activity of Pt.

Electrochemical Corrosion Behavior and Mechanical Properties of Nanocrystalline Ti⁻6Al⁻4V Alloy Induced by Sliding Friction Treatment.

A nanograined (NG) layer with an average grain size of less than 100 nm has been successfully prepared on a Ti⁻6Al⁻4V sheet surface by sliding friction treatment (SFT). The electrochemical corrosion/passive behavior and mechanical properties of an NG Ti⁻6Al⁻4V sheet were examined in this study. A bi-layer passive film that consisted of an outer TiO₂-rich layer and an inner Al₂O₃-rich layer was formed on either an NG or coarse-grained (CG) surface.

Manipulating the degradation behavior and biocompatibility of Mg alloy through a two-step treatment combining sliding friction treatment and micro-arc oxidation.

Manipulating the degradation rate of biomedical Mg alloys has always been a challenge. In this study, a two-step treatment including sliding friction treatment (SFT) and micro-arc oxidation (MAO) was adopted to acquire a unique Mg-based architecture containing three typical layers comprising a MAO coating/nanocrystalline (NC) layer/coarse-grained (CG) matrix. It was found that the modified topmost MAO coating possessed enhanced corrosion resistance, cytocompatibility and hemocompatibility.

Microstructure and Corrosion Behavior of Composite Coating on Pure Mg Acquired by Sliding Friction Treatment and Micro-Arc Oxidation.

For the purpose of detecting the influence of grain structure of a Mg matrix on the microstructure and corrosion resistance of micro-arc oxidation (MAO) coating, prior to MAO processing, sliding friction treatment (SFT) was adopted to generate a fine-grained (FG) layer on coarse-grained (CG) pure Mg surface. It showed that the FG layer had superior corrosion resistance, as compared to the CG matrix, owing to the grain refinement; furthermore, it successfully survived after MAO treatment. Thus, an excellent FG-MAO coating was gained by combining SFT and MAO.

Electrochemical corrosion behavior and elasticity properties of Ti-6Al-xFe alloys for biomedical applications.

The present study is to investigate the microstructural characteristics, electrochemical corrosion behavior and elasticity properties of Ti-6Al-xFe alloys with Fe addition for biomedical application, and Ti-6Al-4V alloy with two-phase (α+β) microstructure is also studied as a comparison. Microstructural characterization reveals that the phase and crystal structure are sensitive to the Fe content. Ti-6Al alloy displays feather-like hexagonal α phase, and Ti-6Al-1Fe exhibits coarse lath structure of hexagonal α phase and a small amount of β phase.