The stable operation of Zn metal anodes under high current densities remains a critical challenge due to the aggravated interfacial parasitic reactions at the inner Helmholtz plane (IHP). Herein, we report an electrode-side preconstruction strategy to preregulate the IHP by constructing a dual-functional Zn surface featuring preferential Zn(002) orientation and SO32--rich interfacial chemistry before cell assembly. After contact with the aqueous ZnSO4 electrolyte, this surface induces resting-induced interfacial reconstruction and promotes the formation of a uniform ZHS-derived solid-electrolyte interphase, enabling homogeneous Zn2+ flux, suppressed hydrogen evolution, and dendrite-free Zn deposition. Operando optical microscopy and theoretical simulations reveal the synergistic roles of crystallographic orientation and anion-rich IHP regulation in stabilizing Zn nucleation and growth kinetics. Consequently, Zn//Zn symmetric cells achieve ultralong cycling stability for 1300 h at 10 mA cm-2 and sustain stable operation for 380 h at an ultrahigh current density of 50 mA cm-2. Moreover, Zn//MnO2 full cells deliver 80% capacity retention after 3000 cycles at 1 A g-1, demonstrating the feasibility of this strategy for high-rate Zn-ion batteries.

Additive manufacturing (AM) offers exceptional control over non-equilibrium solidification of Ti-rich solid-solution alloys, enabling novel microstructures with superior properties. Yet, the AM manipulation of high-concentration titanium alloys-compositions central to or deviating significantly from terminal solid solutions-remains largely unexplored. Here, we reveal how rapid solidification in laser additive manufacturing of Ti-Cu alloys with high Cu contents (25-60 at.%) promotes extensive intermetallic compound (IMC) formation, critically determining mechanical properties. While 25 at.% Cu forms ductile alpha-Ti/Ti2Cu dendrites, higher Cu contents drive sequential incomplete peritectic reactions, producing an unusual microstructure consisting of a cascade of IMC laths, i.e., primary TiCu encapsulated successively by Cu4Ti3, Cu2Ti, and Cu2Ti + Cu4Ti. This exotic, non-equilibrium microstructure, absent in solidification of solid-solution alloys, causes deteriorating plasticity (similar to 4.6 % at 60 at.% Cu) and embrittlement, owing to crystallographic incompatibility and cracking at IMC phase boundaries. By establishing the microstructure-property relationship in AM Ti-Cu high-concentration alloys, this work provides critical insights for mitigating embrittlement by reducing or suppressing IMCs through microstructure manipulation in laser-based fabrications, particularly for laser cladding of Ti coatings on steel using Cu as an interlayer.

The discovery of superconductivity in pressurized Ruddlesden-Popper (RP) nickelates has provided new perspectives on the mechanism of high-temperature superconductivity. Up to now, most experiments concentrated on the lanthanum-related RP phase, so the discovery of new superconducting RP nickelates is highly desirable to reveal their generality. Here we report the observation of superconductivity in Pr4Ni3O10 single crystals above 10 GPa, achieving a maximum Tc of 39 K without saturation, significantly exceeding the value of 25–30 K of La4Ni3O10. Ultrasensitive magnetic susceptibility measurements under high pressure indicate bulk superconductivity with appreciable superconducting volume fractions. Unlike La4Ni3O10, the electronic structure of the high-pressure phase of Pr4Ni3O10 exhibits a dramatic metallization of the σ-bonding band consisting of three d_z^2 orbitals and van Hove singularity of coupled bands of d_x^2-y^2 orbitals near the Fermi level, similar to La3Ni2O7. These findings reveal some generic features of both crystal and electronic structures for high-temperature superconductivity in nickelates and multi-layer cuprates.

The recent discovery of high-temperature superconductivity in pressurized Ruddlesden-Popper nickelates has prompted intensive research into their correlated electron physics. Establishing the diversity of ground states across different Ruddlesden-Popper phases is crucial for elucidating the electron-pairing mechanism in these nickelates. In this work, we synthesized and investigated the long-range ordered 1313-type La3Ni2O7 single crystal. Unlike the bilayer nickelate, the 1313-type La3Ni2O7 exhibits semiconducting behavior at ambient pressure, characterized by a distinct anomaly at 170 K. This behavior is consistently corroborated by magnetic susceptibility and specific heat measurements. 139La nuclear magnetic resonance spectroscopy unambiguously reveals a spin-density-wave transition occurring at 170 K. High-pressure electrical transport measurements reveal pressure-induced metallization but no discernible signs of superconductivity up to 65 GPa. Our findings establish the 1313-type La3Ni2O7 as a platform for investigating the interplay among crystal structure, density-wave orders, and electron pairing in hybrid nickelates.

The interplay among orbital-selective Mott physics, Hund's coupling, tunable structural motifs, and Kondo-like scattering establishes a compelling paradigm for understanding and engineering correlated multi-orbital systems, as vividly exemplified by nickelate superconductors. Here, using high-resolution angle-resolved photoemission spectroscopy combined with theoretical calculations, we systematically investigate the electronic properties of trilayer nickelates. In La4Ni3O10, we observe pronounced interorbital hybridization, whereas in Pr4Ni3O10, the flat d_(z^2 ) band becomes markedly incoherent and diminishes in spectral weight. By contrast, the dispersive d_(x^2-y^2 ) bands retain coherence in both compounds. This striking incoherence/coherence dichotomy identifies an orbital-selective Mott phase modulated by the interlayer Ni-O-Ni bonding angle. The depletion of the d_(z^2 ) orbitals further frustrates the interorbital hybridization and influences the density-wave transition in Pr4Ni3O10. Moreover, the density-wave gap is substantially reduced in Pr4Ni3O10, likely due to extra scattering channels provided by the local moments of Pr3+ cations. Our findings elucidate the intricate interplay among lattice, orbital, spin, and electronic degrees of freedom and reveal a feasible structural control parameter for the multi-orbital correlated state in trilayer nickelates, which provide a concrete framework for understanding the emergence of superconductivity under high pressure.

Triangular-lattice systems host a variety of ground states, ranging from quantum spin liquids to magnetically ordered phases, the latter of which can exhibit a sequence of magnetic phase transitions under applied magnetic fields. Here, we report magnetic and thermodynamic measurements, combined with powder and single-crystal neutron diffraction, on a high-spin, nearly isotropic Mn^2+ triangular-lattice system K_2Mn(SeO_3)_2. The compound undergoes long-range magnetic ordering below T_N∼ 4 K in zero field. Contrary to expectations for an ideal Heisenberg system, the compound adopts an up-down-zero (UD0) magnetic structure down to the lowest temperature (0.05 K), rather than the commonly expected Y-type structure. This UD0 state is, however, highly sensitive to external magnetic fields. For fields applied along the c axis, it is readily destabilized and replaced by the Y-type structure, followed by an up-up-down (UUD) phase corresponding to the 1/3 magnetization plateau. In contrast, when the field is applied within the triangular plane, the system evolves into a canted Y state at a higher critical field. These results reveal that weak anisotropy, though small in magnitude, exerts a strongly orientation-dependent influence, playing a key role in selecting the field-induced phases in this frustrated magnet.

Magnetic refrigeration in the sub-Kelvin regime requires refrigerant materials to retain a large magnetic entropy at low temperatures by suppressing magnetic ordering. Quantum spin liquids (QSLs), which evade long-range magnetic ordering while retaining strong quantum fluctuations to the lowest temperatures, therefore provide a promising platform for realizing high-performance magnetic refrigerants. Here, we investigate the magnetic ground state and the magnetocaloric effect of the hexaaluminate, NdMgAl_11O_19, in which the Nd^3+ ions form a network of triangular lattices. Magnetic susceptibility and specific heat measurements indicate a magnetically dynamic state down to 50 mK, consistent with a QSL state. Specific heat measurements further reveal substantial magnetic entropy retained below 50 mK. Quasi-adiabatic demagnetization measurements demonstrate a superior cooling performance of NdMgAl_11O_19, which can be cooled to 113 mK from 1.9 K by only a small magnetic field change of 2 T. The outstanding refrigeration performance is attributed to the persistent spin fluctuations associated with the QSL-like ground state, together with a large effective g factor and the smallness of the exchange interactions along the easy-axis direction. This study demonstrates that frustration, combined with strong spin-orbit coupling and crystal-electric-field effect in the rare earth magnets provides a promising design principle for next-generation cryogenic magnetic refrigerants.

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.

The solid electrolyte interphase (SEI) governs key electrochemical properties in batteries. While additive-driven SEI engineering constitutes the most promising strategy for tailoring interfacial composition, the impact of specific additives on SEI's dynamic evolution remains unresolved. Herein, we performed operando neutron reflectometry (NR) to quantitatively resolve the SEI's structural dynamics under cycling conditions. Employing model additives with well-defined decomposition mechanisms, fluoroethylene carbonate (FEC) and vinylene carbonate (VC), we establish a robust operando NR framework that enables transferable mechanistic insights for emerging additive systems. Our data reveal contrasting SEI architectures: FEC produces a thin, inorganic-rich SEI (LiF-dominant) that enhances mechanical integrity and cycling stability, while VC yields a flexible organic-dominated SEI which mitigates stress-induced microcracking. These findings provide atomically resolved design principles for advanced electrolyte additives via operando interfacial analysis, advancing high-energy-density Li-ion batteries and beyond.

Hidden order typically manifests as a thermodynamic phase transition without a conventional order parameter, leaving its true nature concealed even at the lowest temperatures. In the frustrated Shastry-Sutherland magnet Nd_2Be_2GeO_7, we observe a related yet fundamentally distinct phenomenon. A sharp specific-heat anomaly appears at 250 mK, but zero-field neutron diffraction and muon spin relaxation detect no static magnetism down to 100 and 30 mK, respectively, pointing to a hidden-order state. Remarkably, this hidden order does not emerge under an applied magnetic field, but instead reveals itself only after the field is applied and subsequently removed where magnetic Bragg peaks appear, albeit with strongly suppressed moments. A glassy state is ruled out by ac susceptibility and specific heat measurements. Complementary μSR measurements reveal coherent spin fluctuations at a rate on the order of gigahertz. Taken together, these results suggest that the system lies in close proximity to the quantum spin liquid and long-range magnetic order state such that a small perturbation can effectively drive the system towards distinct ground states. These findings also distinguish Nd_2Be_2GeO_7 from known frustrated systems, establishing it as a unique platform where the synergistic interplay among the spin-orbit coupling, crystal field, and magnetic frustration leads to unexpected quantum states.

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.

This study investigates the magnetic properties and the cryogenic magnetocaloric effect in Dy2Hf2O7 ceramics, which adopts a defective-pyrochlore structure (space group Fm (3) over barm) due to a low cation radius ratio (r(Dy3+)/r(Hf4+) = 1.14). Magnetic property and heat capacity measurements reveal dominant antiferromagnetic interactions with no long-range magnetic order down to 0.05 K. Analysis of magnetization data using a modified Langevin model confirms the presence of short-range magnetic clusters exhibiting a distinct temperature dependence of the average magnetic moment. The compound demonstrates a moderate magnetocaloric response with a maximum magnetic entropy change (-Delta S-M(max)) of 10.86 J.kg(-1).K-1 and an adiabatic temperature change (-Delta T-ad) of similar to 7.7 K under a 5 T magnetic field change. The wide working temperature range (1-15 K) and the absence of hysteresis make Dy2Hf2O7 a promising candidate for efficient cryogenic magnetic refrigeration. This work highlights the significant role of structural disorder in tailoring magnetocaloric properties for low-temperature cooling applications.

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.

FeNi-based MGs exhibit the most excellent room-temperature mechanical properties among different Fe-based metallic glasses (MGs) systems. However, the glass-forming ability (GFA) of FeNi-based MGs is much lower than that of their counterparts. Thus, uncovering the solidification and anomalous nano-crystallization behavior of FeNi-based MGs is crucial to the development of FeNi-based bulk metallic glasses with larger plasticity and critical size concurrently. Regarding this, a combination of complementary in situ synchrotron radiation high-energy X-ray diffraction, small-angle neutron scattering (SANS), and 3-dimentional atom probe tomography (3-D APT) is used to study solidification and nano-crystallization behavior of Fe48Ni30Mo3B19 liquid and MG. The time–temperature–transformation diagram was successfully depicted via melting spun, in situ solidification, and isothermal annealing methods. We found that the Fe48Ni30Mo3B19 MG can only be prepared via the melt-spinning method to obtain amorphous ribbons, which could contribute to the low activation energy for the nano-crystallization growth Ep. Moreover, during isothermal annealing, the anomalous slow growth behavior in kinetic of the γ-FeNi phase embedded in the amorphous matrix is caused by the Fe and Ni partitioning, and the Mo-enriched region around the nanosized γ-FeNi phase, which is revealed by 3-D APT. These results exhibit a new perspective for understanding the relationship between GFA and nano-crystallization behavior and provide feasible guidance for the development of new γ-FeNi-containing Fe-based BMG composites with desired mechanical properties and GFA.

Here we report the first observed coexistence of quantum spin wave excitation and single-molecule magnet behavior in a fluoride-bridged mixed chromium(III) and dysprosium(III) complex, namely Dy4Cr2(μ3-F)2(mdea)3(piv)10, which shows a large ferrimagnetic ground moment with restricted quantum tunneling gap (< 3.8 × 10−7 cm−1) up to nine levels, leading to an uniaxial magnetic anisotropic energy barrier of 12 cm−1 and opened hysteresis loop at 0.4 K. More importantly, spin wave excitation has been observed by using inelastic neutron scattering spectroscopy, and the data can be well explained by the L&E-band theory with Δ/2 = 2.08 cm−1 and ε(q) = 2.5 cm−1, providing unambiguous evidence for spin wave excitations.

Since the discovery of high-temperature superconductivity, studying the upper critical field and its anisotropy has been crucial for understanding the superconducting mechanism and guiding applications. Here, we perform in situ high-pressure angular-dependent electrical transport measurements on Pr4Ni3O10 single crystals using a custom diamond anvil cell (DAC) rotator, confirming its anisotropic superconductivity. The anisotropy parameter γ, derived from the upper critical fields (μ0Hc2) for H⊥ab and H//ab, is approximately 1.6, decreasing with increasing temperature and approaching 1 near Tc. Comparing effective mass anisotropy and interblock distance in cuprates and iron-based superconductors (FeSCs) reveals that Pr4Ni3O10 single-crystal superconductors are consistent with a two-band model, where intralayer quantum confinement within the unit cell induces interlayer coherence, thereby leading to three-dimensional (3D) superconductivity. This study not only establishes the existence of weakly anisotropic superconductivity in bulk Ruddlesden-Popper nickelates but also provides critical insight into the role of dimensionality in high-temperature superconductivity.

The flexible structure enables nonstructural protein 8 (nsp8) to respond quickly to environmental changes, which are essential for RNA replication and transcription of SARS-CoV-2. In this work, small-angle neutron scattering and AlphaFold2 prediction were applied to characterize the structural change of SARS-CoV-2 nsp8 dimers and tetramers. The results demonstrated that the nsp8 tetramer with a more exposed core domain shows a low thermal stability. The exposed core domain increases its sensitivity to RNA and adapts its structure to interact with RNA. Our work reveals the structural difference between the two forms of SARS-CoV-2 nsp8s in the RNA synthesis process, which partly elucidates the molecular mechanism behind RNA replication of the RNA virus.

The discovery of high-temperature superconductivity in layered nickelates under pressure has recently triggered enormous interest. Studies of these compounds have revealed a density-wave-like transition at ambient pressure, though its connection with superconductivity is still not well understood. Here, we report a detailed mu SR study on single crystals of trilayer nickelate La4Ni3O10 at ambient pressure. We have identified a spin-densitywave (SDW) transition at the temperature of TN similar to 130 K, as well as a broad crossover around 70-100 K. Based on the temperature dependence of the muon precession amplitudes and magnetic susceptibility, we attribute this additional crossover either to a spin reorientation, or to an inhomogeneous SDW ordering.