Electric-field (E) control of magnetism provides a direct route toward low power spin-based technologies by tuning magnetic states without current-driven dissipation. Here, we investigate converse magnetoelectric (CME) coupling in the multiferroic metal-organic framework [(CH3)2NH2]Ni(HCOO)3 (DMA-Ni-F) using electron spin resonance (ESR) as a microscopic probe of local spin environments and magnetic correlations. Temperature-dependent ESR spectra were recorded from 4.2 to 290 K under zero-field cooling (ZFC), electric-field cooling (EFC), and electric-magnetic-field cooling (EHFC), followed by in situ E-field application from +1.25 to −1.25 MV/m and reversed after EHFC. We demonstrate that EFC systematically suppresses the magnetic correlations across 4.2–290 K, evidenced by reduced double integral intensity (I) and broader peak-to-peak linewidth (ΔHpp) of EFC compared to ZFC, while the magnetic field (H) applied in EHFC suppressed the E-induced changes in spin dynamics. Notably, applying E after EHFC yields continuous and reversible modulation of I(E) and Hr(E) in the multiferroic state, providing microscopic evidence of CME coupling in DMA-Ni-F. The observed tunability is consistent with a well-established mechanism, where E-biased DMA+ dipolar configurations reorganize the N–H⋯O hydrogen-bond network and perturb the Ni–O–C–O–Ni chain, thereby modifying the local magnetic environment in the multiferroic DMA-Ni-F MOF.

Electric-field (E) modulation of magnetic order in hybrid materials remains of significant interest for multiferroic metal-organic frameworks. Here, we investigated the spin-resonance response of single-crystal [(CH3)2NH2]Fe(HCOO)3 (Fe-MOF) via X-band electron spin resonance (ESR) under four cooling conditions, including zero-field cooling (ZFC), magnetic-field cooling (HFC), electric-field cooling (EFC), and combined electric- and magnetic-field cooling (EHFC). These measurements revealed protocol-dependent variations in the resonance field (Hr) and double-integral intensity (I) within the magnetically ordered phase below ∼18.5 K (TN). After EFC, E variation from 0 to 2.2 MV/m and back produced small but reproducible Hr shifts (ΔHr ≈ 0.3 mT) and systematic I(E) variations. While under EHFC, E variation from +2.2 to -2.2 MV/m and back produced a larger symmetric modulation (ΔHr ≈ 1.2 mT) and reversible I(E) changes. The electric-field response decreased progressively with increasing temperature, and it became negligible at TN, indicating that the effect was confined to the magnetically ordered phase. These results demonstrated electric-field sensitivity of the resonance response, consistent with dipole-coupled spin interactions in the framework.

P2-type layered oxide cathodes dominate sodium-ion batteries (SIBs) due to exceptional sodium ion kinetics. However, longstanding phase transitions (e.g., P2-to-O2) not only compromise this inherent kinetic advantage but also cause severe stress strain undermining structural stability. Here, we propose a stage-specific chemical design that targetly addresses de-sodiated interlayer O2- repulsion, the structural origin of phase transitions in P2 cathodes. The designed Na0.67Ni0.05Fe0.05Ti0.05Cu0.2Mn0.65O2 (NFTCM) cathode shows a record Na-layer spacing (3.67 Å) with reduced negative charge on oxygen ions, maximally lowering O2--O2- repulsion during the entire desodiation process. As evidenced by in situ X-ray diffraction, the NFTCM cathode shows a true zero-phase-transition behavior with a record-low volume variation of 0.062% upon cycling. This stable, zero-strain Na ions storage behavior contributes to exceptional rate capability (121 mA h/g at 10C) and remarkably stable cycling, retaining 93.7% capacity after 600 cycles. Furthermore, operando neutron diffraction data indicate that the eliminated phase transition also enables a robust oxygen framework, a crucial factor in stabilizing the ion storage process of layered oxides.

Hybrid organic-inorganic metal-organic frameworks (MOFs) have emerged as promising platforms for multiferroicity driven by strong spin-lattice coupling. However, microscopic insight into electric-field (E) control of magnetic excitations remains limited. Here, we investigated the E modulation of spin dynamics in the hybrid perovskite [C(NH2)3]Cu(HCOO)3 (Cu-MOF) single crystal using electron spin resonance (ESR) under controlled ferroic cooling protocols. Distinct ESR responses were observed after zero-field cooling (ZFC), magnetic-field cooling (HFC), electric-field cooling (EFC), and combined electric-magnetic-field cooling (EHFC) demonstrated a pronounced dependence of the magnetic excitations on ferroic history. Systematic variation of E revealed reproducible, polarity-dependent modulation of double-integral ESR intensity, reaching similar to 45-50% at the magnetic ordering temperature (T N) under EFC conditions. It exhibited a more pronounced hysteretic response under EHFC, providing spectroscopic signatures consistent with converse magnetoelectric (CME) coupling. Temperature-dependent measurements uncovered a crossover from domain-mediated behavior below T N to a robust spin-lattice-driven response persisting up to the ferroelectric transition (T c). These results provided new microscopic insight into how electric polarization modulates magnetic excitation spectra in hybrid MOFs and established ESR as a sensitive probe of E-controlled spin dynamics in hybrid multiferroics.

This study investigates the microscopic spin dynamics and anisotropic magnetic behavior in van der Waals kagome magnet Nb3Cl8 by employing electron spin resonance (ESR) spectroscopy on both powder and single-crystal samples over the temperature range of 5 K-300 K. The effective g, peak to peak linewidths (Delta H-pp), and double integrated intensities (I) were extracted from the ESR spectra to analyze the temperature-dependent evolution of spin-orbit coupling and spin-spin interactions. The formation of singlet ground state in single crystal Nb3Cl8 at T*similar to 100 K is observed, evidenced by the maximum Delta H-pp and g at T*, along with the decrease in intensity I, which is consistent to the reported non-magnetic transition in the single-crystal Nb3Cl8. Moreover, the spectral difference between H parallel to c and H perpendicular to c configurations imply subtle magnetic anisotropy in single crystal Nb3Cl8. However, there is no non-magnetic transition was observed in powder Nb3Cl8 since the parameters of Delta H-pp and I keep stable at T*. It might be attributed to the grain averaging and random orientation effects. Our study provides valuable insights into the magnetic interplay in Nb3Cl8 and prove the potential of ESR spectroscopy as a powerful tool for probing the intrinsic magnetism.

Constructing a fluorine (F)-enriched solid electrolyte interphase (SEI) is a well-established approach for stabilizing lithium (Li) metal batteries, yet achieving an SEI with the desired high fluorination efficiency (FE) remains challenging. Herein, we address this by proposing an electrostatic-interaction strategy that employs a fluorinated ionic additive, 4-fluoro-phenylammonium tetrafluoroborate (FPT). Leveraging electrostatic attraction, FP+ cations preferentially adsorb onto the negatively charged Li anode surface within the inner Helmholtz plane (IHP), as supported by systematic theoretical analysis, multiple microscopy characterizations and electrochemical measurements. This unique interfacial configuration effectively suppresses the accumulation of solvent molecules, attracts fluorinated anions and promotes the prior decomposition of FP+, leading to high fluorination efficiency and the formation of a LiF-enriched SEI. Consequently, the Li//Li symmetric cell achieves exceptional cycling stability over 3000 h even at an ultra-high current density of 10 mA cm-2. Furthermore, the derived BF4- anions concurrently construct a protective cathode interphase, which inhibits Al corrosion and electrolyte oxidative decomposition, thus allowing the pure ether-based electrolytes to enable not only stable Li//LiFePO4 but also high-voltage Li//LiNi0.8Co0.1Mn0.1O2 full cells. This work demonstrates a design paradigm centered on targeted molecular attraction to construct a highly fluorinated SEI without requiring high-concentration F-containing species.

Lithium metal batteries (LMBs) experience poor cycling stability mainly due to the interfacial instability of the lithium metal anode and the unavoidable accumulation of electrochemically inactive dead lithium. Here, we report a multifunctional Li3Bi&LiI composite artificial anode interphase that forms in situ via a simple one-step interfacial reaction between BiI3 and lithium metal. This architecture combines the functions of Li3Bi for interfacial coupling and mechanical strength with LiI to improve Li+ transport, extend the Sand's time, and ensure uniform lithium deposition. More importantly, partially dissolved LiI enables a reversible I-/I3 - redox process that continuously reactivates dead lithium into cyclable Li+, directly addressing lithium inventory loss. Benefiting from the synergistic coupling of interfacial stabilization and lithium recycling, the optimized lithium anode achieves ultra-long dendrite-free cycling exceeding 10 000 h and maintains stable operation >450 h even at an ultrahigh current density of 10 mA cm-2. When paired with a LiFePO4 cathode, the LMB retains a 94.4% capacity retention after 500 cycles. This work integrates interfacial stabilization with active lithium recycling in a single protective design, offering a viable strategy toward long-life LMBs.

Cobalt-free Lithium-rich layered oxides (LRLOs) are promising cathodes for low-cost and high-energy-density Li- ion batteries. However, their remarkable capacity comes with challenges including structural degradation, irreversible oxygen release and sluggish kinetics. Herein, we conduct a one-step dual-modified strategy by yttrium doping and Li3PO4 surface modification. Combining density-functional theory calculations with in-situ Xray diffraction and in-situ differential electrochemical mass spectrometry, the Y3+ doping and Li3PO4 nano coating modified LRLOs is demonstrated has an excellent structural stability with enhanced Li+ diffusion kinetics and stabilized oxygen lattice. Excellent rate performance and thermal stability are achieved: high discharge specific capacity of 221 mAh center dot g-1 at room temperature (96.5 % at 1 C after 100 cycles) and incredible discharge specific capacity of 210 mAh center dot g-1 at 55 degrees C (91.8 % at 2 C after 100 cycles). This work resolves the safety and stability issues and provides a feasible strategy for Co-free LRLOs.

The China Spallation Neutron Source (CSNS) is designed and constructed by the Institute of High Energy Physics, Chinese Academy of Sciences. The construction of CSNS includes an 80-MeV Linac, a 1.6-GeV Rapid Cycling Synchrotron (RCS), two beam transport lines, a solid target station of 100 kW, three initial neutron instruments and other utility facilities. Based on limited funding and lack of experience in the high-power proton accelerator and the spallation target, the CSNS design was optimized to an advanced user faculty to fulfill the urgent user demand, with a high performance/cost ratio, and to have the capability for the CSNS phase two project (CSNS-II) to increase the beam power to 500 kW with less investment. The CSNS construction started in October 2011, and finished in March 2018 on schedule, and reached the acceptance parameters. Since then, CSNS has been operating efficiently and stably. In March 2024, the proton beam power on the target was increased to 160 kW. More than 1700 user experiments have been carried out so far, indicating a strong user demand. The design, construction and commissioning of CSNS are presented in this paper.

Li-ion batteries (LIBs) are widely used in mobile devices and electric vehicles, but the traditional layered transition metal cathode material, LiTMO2 (TM=Ni, Co, Mn, or Al), has a low energy density that cannot satisfy the demand of commercial applications. The Li-rich Mn-based layered oxides (LRLOs) are a strong competitor to the traditional layered cathode materials for their specific capacity of more than 200 mAh/g. Due to the high energy density and low cost, Li-rich Mn-based layered oxides (LRLO) have been a promising candidate cathode for next-generation Li-ion batteries. The anionic redox reaction (ARR) in LRLO destabilizes the lattice oxygen, leading to voltage degradation and capacity loss. Although iron-substituted cobalt-free Li-rich materials can achieve less voltage decay, they suffer severe cation disorder and poor kinetics. Here, we develop a simple and feasible high-valent ion doping strategy by doping Mo into Li1.2Ni0.13Fe0.13Mn0.54O2(LNFMO), which expands the Li layer spacing and provides a broader channel for Li+ transport, thereby improving the diffusion kinetics of Li+, effectively suppressing the cation disorder, and further stabilizing the layered structure. As a result, the Mo-doped LRLO exhibits significantly enhanced electrochemical performance, with an initial reversible capacity of 209.48 mAh/g at 0.2 C, and the initial specific capacity increasing from 137.02 mAh/g to 165.15 mAh/g at 1 C. After 300 cycles, specific capacity remains 117.49 mAh/g for the Mo-doped cathode, and the voltage decay decreases from 2.09 mV/cycle to 1.66 mV/cycle. The Mo-doped LRLO is systematically characterized, and the mechanism of cycle stabilization is revealed, which provides an important reference for designing high performance Li-rich cathode.

Crystalline solids exhibiting inherently low lattice thermal conductivity (kappa L) are of great importance in applications such as thermoelectrics and thermal barrier coatings. However, kappa L cannot be arbitrarily low and is limited by the minimum thermal conductivity related to phonon dispersions. In this work, we report the liquid-like thermal transport in a well-ordered crystalline CsAg5Te3, which exhibits an extremely low kappa L value of similar to 0.18 Wm-1K-1. On the basis of first-principles calculations and inelastic neutron scattering measurements, we find that there are lots of low-lying optical phonon modes at similar to 3.1 meV hosting the avoided-crossing behavior with acoustic phonons. These strongly localized modes are accompanied by weakly bound rattling Ag atoms with thermally induced large amplitudes of vibrations. Using the two-channel model, we demonstrate that coupling of the particle-like phonon modes and the heat-carrying wave-like phonons is essential for understanding the low kappa L, which is heavily deviated from the 1/T temperature dependence of the standard Peierls theory. In addition, our analysis indicates that the soft structural framework with liquid-like motions of the fluctuating Ag atoms is the underlying cause that leads to the suppression of the heat conduction in CsAg5Te3. These factors synergistically account for the ultralow kappa L value. Our results demonstrate that the liquid-like heat transfer could indeed exist in a well-ordered crystal. Liquid-like heat transfer is observed and explained in a well-ordered crystal, which hosts soft structural framework with liquid-like motions of the fluctuating/rattling Ag atoms.

Garnet-type Li7La3Zr2O12 (LLZO) is a promising solid electrolyte for all-solid-state batteries due to its structural stability and high Li+ ionic conductivity, but high-purity LLZO crystallizes in a low-conductivity tetragonal phase at room temperature (RT). Al doping stabilizes the cubic structure, yet its impact on Li+ migration is not fully understood. Using Li6.25La3Zr2Al0.25O12 (LLZAO) as a model, we conducted temperature-dependent neutron powder diffraction (NPD), neutron pair distribution function (nPDF), and density-functional theory (DFT) computations. NPD results, supported by nPDF, show Li+ ions at 24d and 96h sites, excluding 48g. Al at 24d adjusts the distribution of Li, improving ionic conductivity near RT. Maximum Entropy Method analyses indicate a temperature-driven 3D Li diffusion pathway of 24d-96h-96h-24d channels, confirmed by DFT. This work will enhance the understanding of Li diffusion and the optimization of ionic conductivity in garnet-type solid electrolytes.

A multi-slit very small angle neutron scattering (MS-VSANS) instrument has been finally accepted at the China Spallation Neutron Source (CSNS). It is the first spallation neutron source based VSANS instrument. MS-VSANS has a good signal-to-noise ratio and can cover a wide scattering vector magnitude range from 0.00028 to 1.4 Å −1 . In its primary flight path, a combined curved multichannel beam bender and sections of rotary exchange drums are installed to minimize the background downstream of the instrument. An exchangeable multi-slit beam focusing system is integrated into the primary flight path, enabling access to a minimum scattering vector magnitude of 0.00028 Å −1 . MS-VSANS has three modes, namely conventional SANS, polarizing SANS and VSANS modes. In the SANS mode, three motorized high-efficiency 3 He tube detectors inside the detector tank cover scattering angles from 0.12 to 35° simultaneously. In the polarizing SANS mode, a double-V cavity provides highly polarized neutrons and a high-efficiency 3 He polarization analyser allows full polarization analysis. In the VSANS mode, an innovative high-resolution gas electron multiplier detector covers scattering angles from 0.016 to 0.447°. The absolute scattering intensities of a selection of standard samples are obtained using the direct-beam technique; the effectiveness of this method is verified by testing the standard samples and comparing the results with those from a benchmark instrument. The MS-VSANS instrument is designed to be flexible and versatile and all the design goals have been achieved.

Abstract Increasing the charging cut‐off voltage (e.g., 4.6 V) to extract more Li ions are pushing the LiCoO2 (LCO) cathode to achieve a higher energy density. However, an inhomogeneous cycled bulk‐to‐surface Li distribution, which is closely associated with the enhanced extracted Li ions, is usually ignored, and severely restricts the design of long lifespan high voltage LCO. Here, a strategy by constructing an artificial solid–solid Li diffusion environment on LCO's surface is proposed to achieve a homogeneous bulk‐to‐surface Li distribution upon cycling. The diffusion optimized LCO not only shows a highly reversible capacity of 212 mA h g−1 but also an ultrahigh capacity retention of 80% over 600 cycles at 4.6 V. Combined in situ X‐ray diffraction measurements and stress‐evolution simulation analysis, it is revealed that the superior 4.6 V long‐cycled stability is ascribed to a reduced structure stress leaded by the homogeneous bulk‐to‐surface Li diffusion. This work broadens approaches for the design of highly stable layered oxide cathodes with low ion‐storage structure stress.

Among the 5d transition metal iridates, Sr2IrO4, which has a layered chalcogenide structure, has received much attention due to its strong spin–orbit coupling (SOC), which produces Mott insulating states and anomalous physical behaviors. In this paper, the microscopic magnetism of Sr2IrO4 is studied with electron spin resonance (ESR) measurements. The Lande factor g of the ferromagnetic resonance signal of Sr2IrO4 shows anomalous behavior compared to typical ferromagnets. It gradually decreases, and the corresponding resonance field Hr increases, with decreasing temperature. The various physical parameters. including the saturated magnetic field Hs derived from M-H, Hr, ΔHpp, the g factor and the intensity I extracted from ESR spectra, are analyzed in detail. Eventually, it is revealed that the anomalous behavior of the g-factor is induced by in-plane Dzyaloshinsky–Moriya interaction (DMI) rather than the SOC effect.

The T0 chopper has the ability to remove the fast neutrons and high-energy gamma rays emitted at time zero of each pulse cycle. The multi-physics instrument of the China Spallation Neutron Source requires high epithermal neutron flux to obtain large momentum transfer, and the traditional single T0 chopper is a disadvantage for the transmission of epithermal neutrons in the long focusing guide. To solve this problem, the two counter-rotating T0 chopper design is proposed that can greatly improve the transmission efficiency of epithermal neutrons. The results of the beam experiment show that compared with the single T0 chopper operating at 50 Hz, the two counter-rotating T0 choppers at the same speed significantly improves the transmission efficiency of epithermal neutrons (especially the shorter wavelength neutrons). For example, when the two blades partially overlap, the transmission efficiencies of 0.05 & Aring;, 0.1 & Aring;, and 0.2 & Aring; wavelength neutrons are increased by 9.4, 4.7, and 4.6 times, respectively, which fully proves that the two counter-rotating T0 chopper design is reasonable, and the experimental results are in line with expectations. The design and application of two counter-rotating T0 choppers at the China Spallation Neutron Source is the first example of this in the world and can be applied to neutron spectrometers with high epithermal neutron flux requirements, and can also be extended to fields such as the energy selection of high-energy particles.

The thermoelectric properties of nine Zintl-phase semiconductors II-I-V (II = Ca, Sr, Ba, I = Cu, Ag, Au, and V = As, Sb, Bi) are studied by using first-principles calculations. The electronic and thermal transport properties are calculated to elucidate the thermoelectric performance. The electron localization functions and crystal orbital Hamilton population show regular and anisotropic bonding in II-I-V, which makes anisotropic thermal and electronic transport properties. The phonon dispersion curve also shows element dependent distributions. We suggest that the regularity of phonon and electron distribution makes the adjusting of thermoelectric performance in P63/mmc type Zintl-phase compounds possible. The mix of ionic and weak covalent bonding leads to the coexistence of soft phonon modes and favorable electronic properties and thus a high figure of merit (0.41-0.94). We also investigate the three phonon scattering properties. The importance of acoustic phonon softening in lowering thermal conductivity is observed. The symmetry-based three-phonon scattering pathways demonstrate the possible intense phonon-phonon scattering. These data provide a deep understanding of the thermoelectric properties in Zintl-phase compounds.

Full-Heusler thermoelectric materials have intrinsically low lattice thermal conductivity. Our first-principles calculations show that Ba2AgSb is a semiconductor with an indirect band gap of 0.49 eV. The electronic band degeneracy and pockets near the Fermi level facilitate electron transport. The short phonon relaxation time, small group velocity (1.89 km s(-1)), and large phonon scattering space reflect the intense phonon-phonon scattering. The large Gruneisen parameter (1.44) accounts for the strong phonon anharmonicity, thus the low lattice thermal conductivity of 0.5 W m(-1) K-1 at 800 K. The isotropic figure of merit with a maximum value of 4.7 at 750 K is comparable to that of reported materials. The distribution of phonon momentum uncovers the important role of Ag in resisting thermal transport. The analysis of symmetry-based phonon-phonon scattering routes reveals the significance of symmetry on phonon scattering. The crystal structure of Ba2AgSb can be used to regulate chemical elements to build high-performance thermoelectric materials. Our calculations provide an effective way to design thermoelectric materials, stimulating the study of full-Heusler materials.

Thermoelectric materials are critical parts in thermal electric devices. Here, Zintl phase BaAgSb in space group of P6 3 /mmc is reported as a promising thermoelectric material in density function theory. The anisotropic lattice thermal conductivity and phonon transport properties are investigated in theory. The strong phonon-phonon scattering in BaAgSb exhibits ultra-low lattice thermal conductivity of 0.59 W⋅m −1 ⋅K −1 along c -axis at 800 K, and high thermoelectric performance ZT = 0.94 at 400 K. The mix of covalent and ionic bond supports high carrier mobility and low thermal conductivity. The unusual features make BaAgSb a potential thermoelectric material.

By using temperature-dependent neutron powder diffraction combined with maximum entropy method analysis, a previously unreported Li lattice site was discovered in the argyrodite Li6PS5Cl solid-state electrolyte. This new finding enables a more complete description of the Li diffusion model in argyrodites, providing structural guidance for designing novel high-conductivity solid-state electrolytes.