Multi-plane imaging based on cascade spintronic terahertz emitters with curved substrates.

As a novel terahertz (THz) source, a spintronic THz emitter (STE) has become a research hot topic recently due to its ultra-broadband emission, powerful scalability, simple fabrication, and ultrawide pump-wavelength range. To optimize the performance of a STE, its spintronic heterostructure has been extensively investigated and its accessories have been also appropriately improved. In this work, a curved substrate of a STE was proposed and utilized to achieve the modulation of the THz wave front as a new degree of freedom.

Atom-Level Tandem Catalysis in Lithium Metal Batteries.

High-energy-density lithium metal batteries (LMBs) are limited by reaction or diffusion barriers with dissatisfactory electrochemical kinetics. Typical conversion-type lithium sulfur battery systems exemplify the kinetic challenges. Namely, before diffusing or reacting in the electrode surface/interior, the Li(solvent) dissociation at the interface to produce isolated Li, is usually a prerequisite fundamental step either for successive Li "reduction" or for Li to participate in the sulfur conversions, contributing to the related electrochemical barriers.

Designing a Periodic Structure with a Composition Gradient Stack Unit to Realize a Good Comprehensive Dielectric Property of Yttrium Iron Garnet Multilayer Film.

YFeO (YIG) thin films are highly needed in microwave devices, but the low saturation magnetization and low dielectric constant greatly limit the application of YIG thin films. It was reported that the ion substitution, for example, Pr, could increase the dielectric constant of YPrFeO (YPrIG). Unfortunately, the dielectric loss would also be significantly increased.

Interfacial Modulation of a Self-Sacrificial Synthesized SnO@Sn Core-Shell Heterostructure Anode toward High-Capacity Reversible Li Storage.

Sn-based anodes are promising high-capacity anode materials for low-cost lithium ion batteries. Unfortunately, their development is generally restricted by rapid capacity fading resulting from large volume expansion and the corresponding structural failure of the solid electrolyte interphase (SEI) during the lithiation/delithiation process. Herein, heterostructural core-shell SnO-layer-wrapped Sn nanoparticles embedded in a porous conductive nitrogen-doped carbon (SOWSH@PCNC) are proposed.

Enhancing the Piezoelectric Sensing of CFO@PDA/P(VDF-TrFE) Composite Films through Magnetic Field Orientation.

Magnetic nanofiller is helpful for improving the piezoelectric properties of P(VDF-TrFE)-based composites, which shows promising potential as a flexible sensor or energy harvester. In this work, we use the interaction between the magnetic nanofiller and magnetic field to modify the structure of CoFeO (CFO)@polydopamine (PDA)/P(VDF-TrFE) composite, in which CFO@PDA works as the nanofiller into the P(VDF-TrFE) matrix. It was found that the magnetic field orientation during polymer curing can significantly increase the content of the β-phase and of the composite.

Structural evolution of MXenes and their composites for electromagnetic interference shielding applications.

Nowadays, the extensive utilization of electronic devices and equipment inevitably leads to severe electromagnetic interference (EMI) issues. Therefore, EMI shielding materials have drawn considerable attention, and great effort has been devoted to the exploration of high-efficiency EMI shielding materials. As a novel kind of 2D transition metal carbide material, MXenes have been widely investigated for EMI shielding in the past few years due to their extraordinary electrical conductivity, large specific surface area, light weight, and easy processability.

Tuning 4f-Center Electron Structure by Schottky Defects for Catalyzing Li Diffusion to Achieve Long-Term Dendrite-Free Lithium Metal Battery.

Lithium metal is considered as the most prospective electrode for next-generation energy storage systems due to high capacity and the lowest potential. However, uncontrollable spatial growth of lithium dendrites and the crack of solid electrolyte interphase still hinder its application. Herein, Schottky defects are motivated to tune the 4f-center electronic structures of catalysts to provide active sites to accelerate Li transport kinetics.

Snapshot spectroscopic Mueller matrix polarimetry based on spectral modulation with increased channel bandwidth.

This paper presents a snapshot spectroscopic Mueller matrix polarimetry based on spectral modulation. The polarization state generator consists of a linear polarizer in front of two high-order retarders, and the polarization state analyzer is formed by two non-polarization beam splitters incorporated with three high-order retarder/linear analyzer pairs. It can simultaneously generate three modulated spectra used for reconstructing the 16 spectroscopic Mueller elements of the sample.

Nonvolatile magnetoelectric coupling in two-dimensional ferromagnetic-bilayer/ferroelectric van der Waals heterostructures.

One of the promising research topics on two-dimensional (2D) van der Waals (vdW) material based devices is the nonvolatile electrical control of magnetism. Usually, it is very hard to tune ferromagnetic or antiferromagnetic ordering by ferroelectric polarization due to strong exchange coupling. The existence of vdW layer spacing, however, which is ubiquitous in 2D materials, makes interlayer magnetic exchange coupling much weaker than interlayer coupling.

Spectroscopic Mueller matrix polarimeter based on spectro-temporal modulation.

A spectroscopic Mueller matrix polarimeter based on spectro-temporal modulation with a compact, low-cost, and birefringent crystal-based configuration has been developed. The polarization state generator and polarization state analyzer in the system consists of a polarizer in front of two high-order retarders with equal thickness and a rotating achromatic quarter wave-plate followed by a fixed analyzer, respectively. It can acquire the 16 spectroscopic elements of the Mueller matrix in broadband with a faster measurement speed than that of the conventional spectroscopic Mueller matrix polarimeter based on a dual-rotating retarder.

Assessing electrochemical properties and diffusion dynamics of metal ions (Na, K, Ca, Mg, Al and Zn) on a CN monolayer as an anode material for non-lithium ion batteries.

We perform first-principles molecular dynamics (FPMD) simulations together with a CI-NEB method to explore the structure, electrochemical properties and diffusion dynamics of a C2N monolayer saturated with various univalent, bivalent and trivalent metal ions. A characteristic irregular adsorption structure consisting of an inner coplanar layer at the large atomic pore and loosely bound outer layer is discovered for all six types of ions. The predicted specific capacities and mean open circuit voltages (OCVs) for them are: 600 mA h g-1, and 0.

Ferroelectrically tunable magnetism in BiFeO/BaTiO heterostructure revealed by the first-principles calculations.

The perovskite oxide interface has attracted extensive attention as a platform for achieving strong coupling between ferroelectricity and magnetism. In this work, robust control of magnetoelectric (ME) coupling in the BiFeO/BaTiO (BFO/BTO) heterostructure (HS) was revealed by using the first-principles calculation. Switching of the ferroelectric polarization of BTO induce large ME effect with significant changes on the magnetic ordering and easy magnetization axis, making up for the weak ME coupling effect of single-phase multiferroic BFO.

A Strategy to Modulate the Bending Coupled Microwave Magnetism in Nanoscale Epitaxial Lithium Ferrite for Flexible Spintronic Devices.

With the development of flexible electronics, the mechanical flexibility of functional materials is becoming one of the most important factors that needs to be considered in materials selection. Recently, flexible epitaxial nanoscale magnetic materials have attracted increasing attention for flexible spintronics. However, the knowledge of the bending coupled dynamic magnetic properties is poor when integrating the materials in flexible devices, which calls for further quantitative analysis.

Flexible Lithium Ferrite Nanopillar Arrays for Bending Stable Microwave Magnetism.

Recent development in magnetic nanostructures has promoted flexible electronics into the application of integrated devices. However, the magnetic properties of flexible devices strongly depend on the bending states. In order to realize the design of new flexible devices driven by an external field, the first step is to make the magnetic properties insensitive to the bending.

Perpendicular Magnetic Anisotropy and Hydrogenation-Induced Magnetic Change of Ta/Pd/CoFeMnSi/MgO/Pd Multilayers.

The perpendicular magnetic anisotropy (PMA) has been achieved in Ta/Pd/CoFeMnSi (CFMS)/MgO/Pd film, in which the Heusler compound CoFeMnSi is one of the most promising candidates for spin gapless semiconductor (SGS). The strong PMA, with the effective anisotropy constant K of 5.6 × 10 erg/cm (5.

Synergetic Effect of DyO and Ca Co-Dopants towards Enhanced Coercivity of Rare Earth Abundant RE-Fe-B Magnets.

Low coercivity is the main disadvantage of RE-Fe-B permanent magnets containing highly abundant rare earths (RE: La, Ce) from the application point of view, even though they exhibit many cost and resource advantages. In this work, an industrial mixed rare earth alloy (RE = LaCePrNd) with a high amount of the more abundant elements was adopted to fabricate RE-Fe-B permanent magnets by means of mechanical alloying accompanied by post-annealing. A synergetic effect towards enhancing the coercivity was observed after co-doping with DyO and Ca, with the coercivity increasing from 2.

Flexible Quasi-Two-Dimensional CoFeO Epitaxial Thin Films for Continuous Strain Tuning of Magnetic Properties.

Epitaxial thin films of CoFeO (CFO) have successfully been transferred from a SrTiO substrate onto a flexible polyimide substrate. By bending the flexible polyimide, different levels of uniaxial strain are continuously introduced into the CFO epitaxial thin films. Unlike traditional epitaxial strain induced by substrates, the strain from bending will not suffer from critical thickness limitation, crystalline quality variation, and substrate clamping, and more importantly, it provides a more intrinsic and reliable way to study strain-controlled behaviors in functional oxide systems.

High Critical Current Density of YBaCuO Superconducting Films Prepared through a DUV-assisted Solution Deposition Process.

Although the solution deposition of YBaCuO (YBCO) superconducting films is cost effective and capable of large-scale production, further improvements in their superconductivity are necessary. In this study, a deep UV (DUV) irradiation technique combined with a low-fluorine solution process was developed to prepare YBCO films. An acrylic acidic group as the chelating agent was used in the precursor solution.