Zhiqi Liu

Tuning Mn sputtering power in MnPt films reveals a correlation between antiferromagnetic ordering and enhanced OER electrocatalytic performance.

Atomically thin magnets are governed by composition, thickness, stacking, strain, defects, substrates, ferroic order, and interfaces. This Review organizes two‐dimensional (2D) magnetism using net magnetization and momentum‐space spin splitting or spin‐polarization patterns as primary coordinates, supplemented by sublattice structure and the symmetry relations between opposite‐spin sublattices. Ferromagnets generally carry a net moment; ferrimagnets can be fully compensated. Conventional antiferromagnets may retain spin‐degenerate bands, while altermagnets permit nonrelativistic alternating spin splitting under dimension‐specific symmetry constraints. M1–M4 reporting classes introduced here distinguish layer‐resolved atomically thin forms, non‐layer‐resolved thin flakes or films, bulk benchmarks, and theoretical candidates or design routes; the evidence category and ordering‐temperature provenance are reported independently. Current experimental support for altermagnetism comes mainly from M2 thin‐film and M3 bulk benchmarks, leaving a fully verified atomically thin M1 altermagnetic phase as an open experimental goal. Most proposed monolayer and few‐layer systems therefore fall within M4, and contested cases clarify the measurements needed for phase assignment. Device readiness is compared qualitatively using operating temperature, readout, switching, domain control, stability, scalability, interface sensitivity, and integration difficulty. Reliable phase assignment and device assessment require complementary measurements from the same material form under matched conditions, ideally on the same specimen or in situ.

Electrochemical water splitting offers a promising route to sustainable hydrogen production, yet the oxygen evolution reaction (OER) remains kinetically sluggish and subject to spin-selection constraints associated with triplet O2. Here, CoTb ferrimagnetic thin films with strong perpendicular magnetic anisotropy (PMA) are used to investigate the relationship between magnetic ordering and OER kinetics. Under a 300 mT magnetic field, the onset potential decreases by ∼96 mV and the Tafel slope by ∼15.1 mV·dec–1, accompanied by reduced charge-transfer resistance. The enhanced OER activity is strongly correlated with magnetic-state regulation and largely retained after field removal. Tb-mediated 3d–4f exchange and strong PMA contribute to regulating and retaining the Co magnetic state, which may influence interactions between Co active sites and oxygen intermediates. This nonvolatile magnetic state may eliminate the need for continuous field application, potentially reducing energy consumption. These findings provide a new perspective for magnetically regulated electrocatalysts.

Semiconductor electronic devices are increasingly constrained by fundamental quantum tunneling effects and charge‐based mechanisms, which severely limit further miniaturization, write‐speed scaling, and environmental robustness of silicon‐based technologies. These limitations are particularly prohibitive for deep‐space exploration, where extreme temperatures, ultra‐strong magnetic fields, and intense radiation rapidly incapacitate conventional electronics without massive shielding. Here, we present an intrinsically resilient, strain‐mediated antiferromagnetic MnIr/PMN‐PT edge processor that operates reliably as a bare die under temperatures up to 500 K, magnetic fields of 55 T, and radiation doses of 1.5 Mrad. By exploiting an Input‐Modulated In Situ Self‐Refreshing Encoding mechanism, the device performs nonlinear feature extraction and classification directly from raw analog signals, enabling an analog computing architecture that requires no time‐frequency transformation. This architecture achieves 99.8% accuracy in speech recognition without digital preprocessing and 100% accuracy in astronaut visual object recognition. Furthermore, an all‐hardware integrated drone vision system demonstrates real‐time in situ command execution and autonomous navigation, delivering a terahertz‐level response frequency and an ultra‐low energy consumption of approximately 0.2 fJ per operation. This work expands the functional scope of antiferromagnetic devices beyond memory and logic, establishing them as a promising materials platform for energy‐efficient physical computing and autonomous intelligence in extreme environments.

Magnetic tunnel junctions are foundational components of spintronic memory, sensing, and computing, and their performance depends critically on the magnetic metallic electrodes. This perspective examines electrode materials through the lens of magnetic order and the distinct microscopic mechanisms that generate spin‐selective tunneling. Conventional ferromagnets, including CoFeB and half‐metallic Heusler alloys, support exchange‐split electronic states and symmetry‐filtered tunneling, whereas compensated collinear and noncollinear antiferromagnets exploit sublattice selectivity, spin–orbit anisotropy, vector spin textures, and magnetic multipoles. Altermagnets provide a collinear, zero‐net‐moment route based on symmetry‐allowed momentum‐dependent spin splitting. Across these material classes, we compare the origins of tunneling polarization, the roles of barrier evanescent states and interface termination, and strategies for electrically writing and reading the relevant magnetic order. This comparison reveals a broader design principle: effective electrode polarization is not a scalar bulk quantity but a momentum‐, orbital‐, symmetry‐, and interface‐resolved transport property. Beyond the pursuit of ever larger tunneling magnetoresistance, future progress will depend on converting the unconventional spin polarization of emerging magnetic metals into electrically addressable, thermally robust, and reproducible tunneling functionality at realistic interfaces.

The oxygen evolution reaction (OER) is central to electrochemical energy conversion and provides a common platform for exploring catalytic concepts across diverse materials systems. While existing reviews primarily focus on specific catalyst families or advanced characterization techniques, practical guidance for researchers entering the field remains comparatively scarce. This review presents a practical framework that connects fundamental OER concepts with experimental workflows, benchmarking strategies, and application‐oriented evaluation. It introduces the interdisciplinary materials landscape and an evidence‐based framework for reaction‐mechanism identification, followed by practical guidance on cell configuration, working‐electrode preparation, reference‐ and counter‐electrode selection, electrolyte control, electrochemical measurements, activity normalization, stability assessment, oxygen‐product verification, and essential reporting practices. Representative catalyst families are discussed from the perspectives of working‐state evolution, degradation processes, and evidence‐based interpretation rather than as a simple catalogue of reported activities. Application‐oriented sections further bridge laboratory catalyst screening with practical devices. By integrating fundamental understanding, experimental implementation, and cross‐disciplinary materials exploration, this review aims to lower the practical barrier to entering OER research while encouraging researchers across materials science to contribute new materials, concepts, and design strategies. We hope that such cross‐disciplinary integration will broaden the OER materials landscape and accelerate the discovery of practically useful catalysts.

Efficient water electrolysis is central to renewable energy storage but remains limited by the sluggish oxygen evolution reaction (OER). Among state-of-the-art catalysts, rutile RuO2 delivers exceptional activity yet suffers from instability and poorly explored spin effects. Here, we demonstrate OER enhancement in altermagnetic RuO2 by interfacial spin pinning from an epitaxial ferromagnetic La2CoO4 layer. Structural microscopy and X-ray photoelectron spectroscopy reveal a chemically sharp, electronically invariant interface, ensuring that performance gains arise from magnetic effects rather than surface chemistry. Field cooling imprints exchange bias and remanent magnetization across the heterostructure, enforcing a pinned antiferromagnetic order in the RuO2 surface without the need for external fields during the catalytic process. The resulting spin polarization lowers spin-selection barriers for O–O coupling and suppresses domain wall scattering, yielding enhanced OER performance, reduced charge transfer resistance, and markedly improved durability. First-principles calculations uncover altermagnetic spin splitting in RuO2, establishing interfacial spin engineering as a powerful and composition-independent lever for tuning antiferromagnetic catalysts, opening a new frontier for magnetically regulated electrocatalysis.

Magnetostriction, a fundamental phenomenon bridging magnetism and mechanics, has enabled a broad spectrum of applications. For almost two centuries, it has been mainly investigated for ferromagnets. Regarding the magnetostriction of antiferromagnets (AFMs), limitedly known examples for both conventional collinear AFMs and noncollinear AFMs predominantly exhibit nonsaturating magnetic-field dependence. Herein, we report an easily saturated magnetostriction effect in a prototypical altermagnet─MnTe, which is an emerging class of collinear AFMs with special crystal symmetries. For high-quality MnTe single crystals, the magnetostriction saturates under a moderate field of ∼0.7 T with an intriguing 2-fold-symmetry anisotropy. First-principles calculations reveal that the saturated and anisotropic magnetostriction originates from symmetry-allowed coupling between elastic strain and its Néel order parameter. These findings break the traditional wisdom on antiferromagnetic magnetostriction.

The modulation of oxygen evolution reaction (OER) performance in oxide thin films is essential for understanding structure–activity relationships. Recently, we found that ferromagnetic Ruddlesden–Popper phase La ₂ CoO ₄ thin films exhibit superior catalytic activity compared to its perovskite analogue LaCoO ₃ [Z. Meng, Y. Qi, P. Qin, X. Zhou, X. Wang, H. Chen, L. Liu, G. Zhao, Z. Duan, J. Liu, Q. Zhang, P. Tang and Z. Liu, Nano Lett. 25 (2025) 4887]. Here, we further investigate the OER performance of La ₂ CoO ₄ thin films by tuning thickness and introducing a RuO ₂ buffer layer. The intrinsic activity of La ₂ CoO ₄ is found to be independent of thickness, while its stability strongly depends on thickness, with thinner films showing rapid degradation, indicating that thickness alone cannot enhance activity. In contrast, the introduction of a RuO ₂ layer significantly improves OER performance, particularly at low overpotentials, and introduces a new thickness dependence. Further analysis suggests that interfacial intermixing during PLD growth may occur, leading to compositionally modified regions or new active phases. By tuning the La ₂ CoO ₄ overlayer thickness, a trade-off between activity and stability is revealed, governed by the depth distribution of active regions. These results highlight the distinct roles of thickness and intermixing in determining catalytic performance.