Noncollinear Magnetic Structures in the Chiral Antiperovskite β-FeSeO.

We present the magnetic properties of the chiral, polar, and possibly magnetoelectric antiperovskite β-FeSeO as derived from magnetization and specific-heat measurements as well as from powder neutron diffraction and Mössbauer experiments. Our macroscopic data unambiguously reveal two magnetic phase transitions at ≈ 103 K and ≈ 78 K, while Rietveld analysis of neutron powder diffraction data reveals a noncollinear antiferromagnetic structure featuring magnetic moments in the - plane of the trigonal structure and a ferromagnetic moment along . The latter is allowed by symmetry between and , weakly visible in the magnetization data yet unresolvable microscopically.

Surface superconductivity in the topological Weyl semimetal t-PtBi.

Topological superconductivity is a promising concept for generating fault-tolerant qubits. Early experimental studies looked at hybrid systems and doped intrinsic topological or superconducting materials at very low temperatures. However, higher critical temperatures are indispensable for technological exploitation.

Thirty Years of Hide-and-Seek: Capturing Abundant but Elusive M@(8)-C Isomer, and the Study of Magnetic Anisotropy Induced in Dy Ion by the Fullerene π-Ligand.

Our knowledge about endohedral metallofullerenes (EMFs) is restricted to the structures with sufficient kinetic stability to be extracted from the arc-discharge soot and processed by chromatographic and structural techniques. For the most abundant rare-earth monometallofullerene M@C, experimental studies repeatedly demonstrated (9) and (6) carbon cage isomers, while computations predicted equal stability of the "missing" (8) isomer. Here we report that this isomer is indeed formed but has not been recovered from soot using standard protocols.

Synthesis and properties of SrLaNiWO, a new S = 1 triangular lattice magnet.

Magnetic materials featuring triangular arrangements of spins are frequently investigated as platforms hosting magnetic frustration. Hexagonal perovskites with ordered vacancies serve as excellent candidates for two-dimensional triangular magnetism due to the considerable separation of the magnetic planes. In this work, the effects of chemical pressure on the ferromagnetic ground state of BaLaNiWO by substitution of Ba with Sr to produce SrLaNiWO are investigated.

Stabilization Strategies of Lithium Metal Anode Toward Dendrite-Free Lithium-Sulfur Batteries.

Lithium-sulfur (Li-S) batteries are considered as a most promising rechargeable lithium metal batteries because of their high energy density and low cost. However, the Li-S batteries mainly suffer the capacity decay issue caused by the shutting effect of lithium polysulfides and the safety issues arising from the Li dendrites formation. This review outlines the current issues of Li-S batteries.

Separating Cationic and Anionic Redox Activity in the Lithium-Rich Antiperovskite (LiFe)SO.

Lithium-rich antiperovskites promise to be a compelling class of high-capacity cathode materials due to the existence of both cationic and anionic redox activity. Little is however known about the effect of separating the electrochemical cationic process from the anionic process and the associated implications on the electrochemical performance. In this context, we report the electrochemical properties of the illustrative example of three different (LiFe)SO materials with a focus on separating cationic from anionic effects.

Observation of a spontaneous anomalous Hall response in the MnSi d-wave altermagnet candidate.

Phases with spontaneous time-reversal ( ) symmetry breaking are sought after for their anomalous physical properties, low-dissipation electronic and spin responses, and information-technology applications. Recently predicted altermagnetic phase features an unconventional and attractive combination of a strong -symmetry breaking in the electronic structure and a zero or only weak-relativistic magnetization. In this work, we experimentally observe the anomalous Hall effect, a prominent representative of the -symmetry breaking responses, in the absence of an external magnetic field in epitaxial thin-film MnSi with a vanishingly small net magnetic moment.

Raman scattering owing to magneto-polaron states in monolayer transition metal dichalcogenides.

Magneto-optical measurements are fundamental research tools that allow for studying the hitherto unexplored optical transitions and the related applications of topological two-dimensional (2D) transition metal dichalcogenides (TMDs). A theoretical model is developed for the first-order magneto-resonant Raman scattering in a monolayer of TMD. A significant number of avoided crossing points involving optical phonons in the magneto-polaron (MP) spectrum, a superposition of the electron and hole states in the excitation branches, and their manifestations in optical transitions at various light scattering configurations are unique features for these 2D structures.

Influence of magnetic field on electron beam-induced Coulomb explosion of gold microparticles in transmission electron microscopy.

In this work we instigated the fragmentation of Au microparticles supported on a thin amorphous carbon film by irradiating them with a gradually convergent electron beam inside the Transmission Electron Microscope. This phenomenon has been generically labeled as "electron beam-induced fragmentation" or EBIF and its physical origin remains contested. On the one hand, EBIF has been primarily characterized as a consequence of beam-induced heating.

Cation exchange synthesis of AgBiS quantum dots for highly efficient solar cells.

Silver bismuth sulfide (AgBiS) nanocrystals have emerged as a promising eco-friendly, low-cost solar cell absorber material. Their direct synthesis often relies on the hot-injection method, requiring the application of high temperatures and vacuum for prolonged times. Here, we demonstrate an alternative synthetic approach a cation exchange reaction.

Operando Studies of Bismuth Nanoparticles Embedded in N, O-Doped Porous Carbon for High-Performance Potassium-Ion Hybrid Capacitor.

A highly viable alternative to lithium-ion batteries for stationary electrochemical energy-storage systems is the potassium dual-ion hybrid capacitor (PIHC), especially toward fast-charging capability. However, the sluggish reaction kinetics of negative electrode materials seriously impedes their practical implementation. In this paper, a new negative electrode Bi@RPC (Nano-bismuth confined in nitrogen- and oxygen-doped carbon with rationally designed pores, evidenced by advanced characterization) is developed, leading to a remarkable electrochemical performance.

Tunable positions of Weyl nodes via magnetism and pressure in the ferromagnetic Weyl semimetal CeAlSi.

The noncentrosymmetric ferromagnetic Weyl semimetal CeAlSi with simultaneous space-inversion and time-reversal symmetry breaking provides a unique platform for exploring novel topological states. Here, by employing multiple experimental techniques, we demonstrate that ferromagnetism and pressure can serve as efficient parameters to tune the positions of Weyl nodes in CeAlSi. At ambient pressure, a magnetism-facilitated anomalous Hall/Nernst effect (AHE/ANE) is uncovered.

Covalency magnetic axiality in Nd molecular magnets: Nd-photoluminescence, strong ligand-field, and unprecedented nephelauxetic effect in fullerenes NdMN@C (M = Sc, Lu, Y).

Nd-based nitride clusterfullerenes NdMN@C with rare-earth metals of different sizes (M = Sc, Y, Lu) were synthesized to elucidate the influence of the cluster composition, shape and internal strain on the structural and magnetic properties. Single crystal X-ray diffraction revealed a very short Nd-N bond length in NdScN@C. For Lu and Y analogs, the further shortening of the Nd-N bond and pyramidalization of the NdMN cluster are predicted by DFT calculations as a result of the increased cluster size and a strain caused by the limited size of the fullerene cage.

A High-Energy Tellurium Redox-Amphoteric Conversion Cathode Chemistry for Aqueous Zinc Batteries.

Rechargeable aqueous zinc batteries are potential candidates for sustainable energy storage systems at a grid scale, owing to their high safety and low cost. However, the existing cathode chemistries exhibit restricted energy density, which hinders their extensive applications. Here, a tellurium redox-amphoteric conversion cathode chemistry is presented for aqueous zinc batteries, which delivers a specific capacity of 1223.

Spinon Heat Transport in the Three-Dimensional Quantum Magnet PbCuTe_{2}O_{6}.

Quantum spin liquids (QSLs) are novel phases of matter which remain quantum disordered even at the lowest temperature. They are characterized by emergent gauge fields and fractionalized quasiparticles. Here we show that the sub-kelvin thermal transport of the three-dimensional S=1/2 hyperhyperkagome quantum magnet PbCuTe_{2}O_{6} is governed by a sizeable charge-neutral fermionic contribution which is compatible with the itinerant fractionalized excitations of a spinon Fermi surface.

Unusual Low-Energy Collective Charge Excitations in High- Cuprate Superconductors.

Despite decades of intensive experimental and theoretical efforts, the physics of cuprate high-temperature superconductors in general, and, in particular, their normal state, is still under debate. Here, we report our investigation of low-energy charge excitations in the normal state. We find that the peculiarities of the electronic band structure at low energies have a profound impact on the nature of the intraband collective modes.

Dimerization of a Reactive Azaacene Diradical: Synthesis of a Covalent Azaacene Cage.

Two series of regioisomeric dicyanomethylene substituted dithienodiazatetracenes with formal para- or ortho-quinodimethane subunits were synthesized and characterized. Whereas the para-isomers (p-n, diradical index y =0.01) are stable and isolable, the ortho-isomer (y =0.

Combined structural analysis and cathodoluminescence investigations of single Pr-doped CaNbO nanosheets.

Due to the novel properties of both 2D materials and rare-earth elements, developing 2D rare-earth nanomaterials has a growing interest in research. To produce the most efficient rare-earth nanosheets, it is essential to find out the correlation between chemical composition, atomic structure and luminescent properties of individual sheets. In this study, 2D nanosheets exfoliated from Pr-doped KCaNbO particles with different Pr concentrations were investigated.

Realizing Highly-Ordered Laser-Reduced Graphene for High-Performance Flexible Microsupercapacitor.

Laser reduction of graphene oxide (GO) with direct-write technology is promising to develop miniaturized energy storage devices because of highly flexible, mask-free, and chemical-free merits. However, laser reduction of GO is often accompanied with deflagration (spectacular and violent deoxygenating reaction), leading reduced graphene oxide (rGO) films into brittle and irregular internal structure which is harmful to the applications. Here, a pre-reduction strategy is demonstrated to avoid this deflagration and realize a uniform laser-reduced GO (LrGO) matrix for the application of flexible micro-supercapacitors (MSCs).

Exchange Bias Effect of Ni@(NiO,Ni(OH)) Core/Shell Nanowires Synthesized by Electrochemical Deposition in Nanoporous Alumina Membranes.

Tuning and controlling the magnetic properties of nanomaterials is crucial to implement new and reliable technologies based on magnetic hyperthermia, spintronics, or sensors, among others. Despite variations in the alloy composition as well as the realization of several post material fabrication treatments, magnetic heterostructures as ferromagnetic/antiferromagnetic coupled layers have been widely used to modify or generate unidirectional magnetic anisotropies. In this work, a pure electrochemical approach has been used to fabricate core (FM)/shell (AFM) Ni@(NiO,Ni(OH)) nanowire arrays, avoiding thermal oxidation procedures incompatible with integrative semiconductor technologies.

Two-Step Synthesis of B N -Doped Polycyclic Aromatic Hydrocarbon Containing Pentagonal and Heptagonal Rings with Long-Lived Delayed Fluorescence.

Pentagon-heptagon embedded polycyclic aromatic hydrocarbons (PAHs) have aroused increasing attention in recent years due to their unique physicochemical properties. Here, for the first time, this report demonstrates a facile method for the synthesis of a novel B N -doped PAH (BN-2) containing two pairs of pentagonal and heptagonal rings in only two steps. In the solid state of BN-2, two different conformations, including saddle-shaped and up-down geometries, are observed.

A Review on Nano Ti-Based Oxides for Dark and Photocatalysis: From Photoinduced Processes to Bioimplant Applications.

Catalysis on TiO nanomaterials in the presence of HO and oxygen plays a crucial role in the advancement of many different fields, such as clean energy technologies, catalysis, disinfection, and bioimplants. Photocatalysis on TiO nanomaterials is well-established and has advanced in the last decades in terms of the understanding of its underlying principles and improvement of its efficiency. Meanwhile, the increasing complexity of modern scientific challenges in disinfection and bioimplants requires a profound mechanistic understanding of both residual and dark catalysis.

A Newly Designed High-Strength Tool Steel with High Wear and Corrosion Resistance.

In this study, a newly developed high-strength cast Fe81Cr15V3C1 (wt%) steel with a high resistance against dry abrasion and chloride-induced pitting corrosion is presented. The alloy was synthesized through a special casting process that yielded high solidification rates. The resulting fine, multiphase microstructure is composed of martensite, retained austenite and a network of complex carbides.