Research articles

In this work, we focused on Wadsley–Roth phase TiNb₂O₇ with an octahedral network as a negative electrode material for lithium-ion batteries and investigated the effect of the network structure, which is considered to form Li⁺ conduction pathways, on the electrode properties. To this end, we prepared samples with different charge/discharge properties and generated atomic configurations that simultaneously reproduce both total scattering and Bragg profile data. Topological analyses based on persistent homology demonstrated that the network disorder significantly degrades the electrode properties.

The 1D transition metal tetra-chalcogenides, NbTe₄, with inherent structural and optical anisotropy, has been used to develop a polarization-sensitive photodetector. The NbTe₄ flakes-based device displays pronounced anisotropic photodetection properties with a dichroic ratio of 1.16 at 671 nm and 1.25 at 1064 nm. It also demonstrates a significant photothermoelectric effect, enabling a broad spectral response from the visible to near-infrared spectrum (532-1064 nm).

We report on the fabrication and electrical characteristics of In₂Te₃ thin films grown on h-BN using molecular beam epitaxy(MBE). Cross-sectional scanning transmission electron microscopy images showed an atomically clean and abrupt interface between In₂Te₃ and h-BN substrates. The MBE-grown In₂Te₃ electronic devices exhibited superior electrical properties compared to previously reported In₂Te₃ field effect transistors(FETs) and In₂Te₃-based Schottky diodes.

In this article we studied the evolution of band anisotropy in strained VO₂(101) thin films. We found out that strain works as a control agent for the anisotropy and thus controls the features of VO₂ bands structure. For this crystal orientation a large strain corresponds to a more homogeneous electronic structure of VO₂. This impacts the electrons population redistribution between d_|| and π bands, the screening length and the effective mass. By controlling the anisotropy and the band structure properties our results can ease the integration of VO₂ into complex electronics.

Dynamical and structural heterogeneities play important roles in glass transition. However, the relationship between these heterogeneities has not been fully revealed. In this study, we simultaneously observed these heterogeneities near the glass transition temperature in Zr₅₀Cu₄₀Al₁₀ via five-dimensional scanning transmission electron microscopy (5D-STEM), which can record the spatiotemporal distribution of diffraction patterns. We estimated local dynamics from the temporal series of diffraction patterns and local structural orders from the diffraction patterns themselves. By performing this estimation for all scanning points, we visualized the heterogeneities and found the correlation between them, which indicated that ordered structures tended to have slow dynamics.

Metasurface-based sensors provide a battery-free sensing solution for maintaining numerous IoT devices with little human resources. However, the conventional method exploited resonant mechanisms associated with multiple physical parameters through different frequencies, although available frequencies were strictly limited. We report the first sensor design approach using circuit-based metasurfaces that offer a higher degree of freedom to design time-varying scattering profiles associated with multiple physical properties at a single frequency. Our prototype detects light intensity and temperature with an excellent determination coefficient above 0.96 via a machine-learning technique.

First-principles calculations demonstrated that the substitution of In for Ge has a lower energy barrier for phase transition than the substitution of In for Co in MnCoGe alloys. ELF calculations further reveal the regulated hysteresis’s atomic coordination origin. This theoretical prediction is completely verified by combining neutron, magnetic and calorimetric measurements; consequently, a largely enhanced barocaloric effect has been achieved.

This study introduces a technique for utilizing conventional lithium-ion battery electrodes in all-solid-state batteries. By infiltrating a solid electrolyte solution into the porous electrode, the effects based on the morphology of the active material were investigated. In poly-crystalline materials, high coverage and the formation of a thin side reaction layer were observed. Consequently, the infiltration process also confirmed the superior performance of poly-crystalline materials.

Oxynitride-supported Ni catalysts exhibit much higher activity than oxide-supported Ni catalysts for ammonia decomposition reaction. Ammonia is activated at nitrogen vacancy sites on the surface of oxynitride in close vicinity to the supported Ni nanoparticles rather than on the Ni surface, and therefore the catalytic performance is dominated by ease of nitrogen vacancy formation on the catalyst surface.

Cross-luminescence (CL) in a barium fluoride arising from the recombination of a valence band electron and a core band hole, and intrinsically intense self-trapped exciton (STE) luminescence occurs. Herein, we report a redshift in the CL emission wavelength with high-pressure application via a sapphire anvil cell. Increasing the pressure decreases the core-valence bandgap due to the downward expansion of the valence band. The onset of a phase transition from a cubic crystal structure to an orthorhombic crystal structure at 3.7 GPa inhibited the recombination of conduction band electrons and self-trapped holes, leading to the disappearance of the STE emission.

On-demand underwater adhesives with excellent adhesive and gentle detachment properties enable stable connections to various biomedical devices and bio-interfaces and avoid the risk of harmful tissue damage upon detachment. Herein, we present a Janus hydrogel adhesive that can reversibly switch its adhesion strength, which is controlled by temperature, using a thermoresponsive polymer and mussel-inspired molecules. This thermoswitchable adhesive hydrogel displays both strong adhesion and gentle detachment with an over 1,000-fold gap in underwater adhesion strength. The thermoswitchability of the hydrogel adhesives, with its robust adhesion and gentle detachment, offers significant potential for biomedical applications characterized by minimally invasive procedures.

A “plasmashock” method was developed to synthesize metal nanoparticles anchored on different kinds of carbonaceous substrates using liquid salt solution precursors. These self-supporting, nanoparticles-loaded carbon fabrics are mechanically robust and tested as antibacterial substrate and electrocatalysts for reducing carbon dioxide and nitrite.

Sulfur particles disperse in a functionalized reduced graphite oxide (rGO) cathode with a binder-less polymer electrolyte and a dual-anion ionic liquid-containing cross-linked PEO–LiFSI_0.1(Pyr₁₄TFSI)_0.4 are hot-pressed into an integrated electrode, serving as both the cathode and electrolyte. Dual-anion solid polymer electrolyte and rGO-functional integrated sulfur electrode presents a novel method to improve the electrochemical properties of lithium-sulfur batteries.

We investigated the origins of charge density wave (CDW) mechanisms in the bi-layered kagome metal ScV₆Sn₆ by comparing its electronic structure with that of its isostructural counterpart YV₆Sn₆, which does not exhibit a CDW state. Our ARPES measurements reveal that the Van Hove singularity (VHS) nesting mechanism may not be valid in the CDW state. In ScV₆Sn₆, the electronic structure shows a CDW-induced band gap accompanied by anomalous band dispersion near the M point of the Brillouin zone. These findings provide experimental evidence for the origin of CDW in vanadium-based kagome metals.

Noise and impact hazards are pervasive in engineering, necessitating materials capable of absorbing both sound and stress wave energy. Here, we present bioinspired metamaterials with exceptional sound-absorbing and mechanical properties using a weakly-coupled design strategy. These materials incorporate multi-layered resonators for superior acoustic performance and cambered cell walls for enhanced structural strength. They achieve an average absorption coefficient of 0.80 across the 1.0 to 6.0 kHz range, all within a sleek 21 mm thickness. Furthermore, the design transitions failure modes from catastrophic to progressive, resulting in a remarkable 558.4% increase in energy absorption compared to conventional designs.

We demonstrate a 1D linear potential system in superconducting films by creating vortex-antivortex pairs linked by either quantized or unquantized magnetic flux. Our study of vortex pair manipulation and thermal behavior reveals a 1D force mediated by unquantized magnetic flux. This discovery suggests a universal mechanism for forming 1D force systems, offering a new paradigm in the physics of 1D forces.

The addition of Li2O-B2O3-Al2O3 (LBA) sintering aid to Li_6.1Ga_0.3La₃Zr₂O₁₂ (LGLZO) solid electrolytes enhances grain boundary characteristics and reduces porosity. This modification leads to a substantial increase in ionic conductivity and mechanical stability, while effectively preventing Li dendrite formation. The optimized LGLZO sample with LBA exhibits improved long-term cycling performance, making it a promising candidate for high-performance all-solid-state batteries. These findings underscore the critical role of grain boundary engineering in enhancing the electrochemical properties of garnet-type electrolytes.

We have fabricated artificial grain boundaries in K-doped BaFe₂As₂ (Ba122:K), one of the Fe-based superconductors. The crystalline orientation map, acquired through the scanning precession electron diffraction measurements, revealed that spontaneous connectivity modification occurred at the grain boundary, which may mitigate weak-link behavior. Specifically, a self-field critical current density J_c of over 0.1 MA/cm² across the grain boundary with misorientation angles up to 24° was recorded even at 28 K. This performance surpasses the grain boundary properties of hitherto reported Fe-based superconductors. Our results highlight the exceptional potential of Ba122:K for polycrystalline applications and pave the way for next-generation superconducting magnets.

Radiotherapy (RT) faces challenges like hypoxia-induced tumor resistance and weak antitumor immune responses. This study developed a nanosystem using mesoporous silica nanoparticles (MSNs), R837, and manganese peroxide (Mn/ZnO₂). The MSN@R837-Mn/ZnO₂ nanoparticles showed precise tumor targeting, controlled drug release in acidic conditions, and enhanced MRI sensitivity, boosting RT efficacy by reducing hypoxia and immunosuppression. Tumor cells treated with RT and these nanoparticles had less oxidative stress, improved hypoxia, and normalized blood vessels. Remarkably, all mice in the RT+PD-1+MSN@R837-Mn/ZnO₂ group achieved complete tumor regression and extended survival, with no toxicity observed, indicating its potential for cancer imaging and treatment.