Jing Zhang

Multilayer Transition Metal Dichalcogenides

In article number 2412737, Stephen J. Pearton, Jihyun Kim, Gwan-Hyoung Lee, and co-workers illustrate multilayer transition metal dichalcogenides (ML-TMDs) with varying twist angles. The magnified insets display fully-commensurate, reconstructed, and fully-incommensurate Moiré superlattice structures, emphasizing the influence of twist angles on interlayer interactions. This visualization highlights the tuneable properties of ML-TMDs for potential applications in nanoelectronics, optoelectronics, and quantum technologies.

By synergizing charge supplementation with a multiphase electrode strategy, record-breaking ultrahigh durability and power output for TENGs is achieved, and further integrated a self-developed ultralow-power management circuit to enable fully self-sustained, continuous operation of marine IoT nodes with GPS functionality—powered solely by TENG energy.

Abstract

The sustainable operation of marine Internet of Things (IoT), as a critical enabler for marine resource utilization, is hindered by the lack of robust energy solutions capable of powering advanced functionalities in unpredictable oceanic environments. Here, a self-sustainable, highly reliable triboelectric nanogenerator system is presented that synergizes a non-contact architecture with dynamic charge supplementation and multiphase electrode design to overcome persistent limitations in durability, energy storage, and water wave adaptability. The system achieves a 3-fold enhancement in output charge with 97% performance retention over 20 million cycles—5.2 times more durable than state-of-the-art counterparts. A chaotic double-pendulum structure further broadens operational bandwidth to 0.4–1.0 Hz with the charge accumulation rate of 4.6 times, enabling record-breaking average power density of 13.53 W m⁻³ Hz⁻¹. Furthermore, an adaptive ultralow-powered (244 nW) integrated management circuit with on-demand direct current supply functionality ensures a 394-fold energy storage speed, successfully sustaining real-time GPS communication and water quality monitoring in autonomous buoys. This work establishes a scalable, maintenance-free paradigm for marine energy harvesting, directly addressing the energy paradox in IoT deployment while advancing sustainable resource management and climate resilience strategies.

Through a symmetry-reduction strategy employing structural motif engineering, ultra-low-symmetry Ta₂PtSe₇ atomic layers featuring unprecedented 20.1 Å-long [Ta₄Pt₂Se₁₄] motifs were discovered. This extended motif architecture enables exceptional in-plane anisotropy, confirmed by direction-dependent optical and electrical characteristics. Notably, the bandgap-independent photoresponse of 2D Ta₂PtSe₇ achieves 27 V/W at 10.6 µm while maintaining >70% of its initial photocurrent throughout 50 bending cycles.

Abstract

The limited ability of traditional 2D anisotropic materials to meet next-generation anisotropic device demands necessitates innovative design strategies. To address this challenge, a symmetry-reduction approach is proposed that enhances in-plane anisotropy by extending structural motifs to lower crystal symmetry. Implementing this design principle, a novel van der Waals material, Ta₂PtSe₇ atomic layers is successfully developed, featuring record-breaking [Ta₄Pt₂Se₁₄] structural motifs with an unprecedented length of 20.1 Å. This unique architecture endows Ta₂PtSe₇ with remarkable intrinsic in-plane anisotropy, manifesting in strongly direction-dependent optical and electrical characteristics. The developed Ta₂PtSe₇-based photodetector demonstrates exceptional broadband responsiveness across an expansive spectral range from visible to long-wavelength infrared (LWIR; 671 nm–10.6 µm). Particularly noteworthy is its outstanding performance under low operating voltage (0.1 V), achieving a high responsivity of 27 V W⁻¹ at 10.6 µm illumination – a significant advancement in LWIR detection capabilities. Furthermore, flexible device configurations exhibit excellent mechanical robustness, maintaining over 70% of initial photocurrent after 50 bending cycles, demonstrating promising potential for flexible optoelectronics. This study proposes a novel structural motif engineering strategy to design anisotropic materials, exemplified by Ta₂PtSe₇’s exceptional in-plane anisotropy, broadband photoresponse, and mechanical robustness, enabling high-performance anisotropic optoelectronic devices.

Moiré superstructures locally modulate the reactivity of graphene toward chemical functionalization. However, a quantitative characterization of this effect at the subnanometer scale constitutes a challenge. Using atomic hydrogen as a probe for local reactivity permits the analysis of how the moiré-induced corrugation correlates with an enhanced reactivity on the moiré domains of epitaxial graphene on Pt(111).

Abstract

The periodic patterning induced by moiré superstructures enables the synthesis of spatially functionalized graphene surfaces owing to changes in the local reactivity of the material. However, quantitative characterization of the effect of different moiré patterns remains elusive. By exploiting the large number of moiré superstructures appearing on epitaxial graphene grown on a Pt(111) surface, this stud examines the effect of moiré-induced corrugation on the local reactivity toward hydrogenation. This work combines atomically resolved scanning tunneling microscopy alongside density functional theory and Monte Carlo simulations of hydrogen chemisorption. The findings reveal a more efficient hydrogen adsorption onto moiré patterns compared to flat graphene, with a marked selectivity toward the most topographically protruding areas of the moiré. This moiré-induced enhancement of the hydrogenation efficiency is slightly increased on the most corrugated structures, which also display longer residence times and a higher stability against thermal desorption.

Through the exposure-synergized heating strategy, a dual-cross-linked network that combines flexibility and rigidity is constructed, resulting in a dissolution difference between the exposed and unexposed regions. This strategy facilitates the fabrication of precise patterns at multiple scales, including millimeter, micrometer, and nanometer dimensions, on substrates. This study will offer new perspectives for applications in flexible nanofabrication.

Abstract

Modulating the molecular design of polymers to create highly integrated flexible structures with superior mechanical properties and precise, on-demand patterning has considerable potential for applications in mechanical, electronic, and biomedical fields. However, achieving an optimal balance of high-strength, high-toughness, and low-defect patterning within micro and nanoscale dimensions remains challenging. This study investigates photothermally synergistic cross-linked three-component-patterned materials (TCPMs) for the first time. These materials form a cross-linked network through a photoinduced thiol–ene click reaction of polythiol–norbornene and a thermally initiated Diels–Alder (D–A) reaction of difuran-maleimide, enabling controlled solubility switching and facilitating directional pattern transfer after development. On characterizing the mechanical behavior and pattern quality, TCPM achieves a pattern line width of 136 nm, a sensitivity of 25.4 mJ cm⁻², an elongation rate of 330%, and an elastic modulus of 1.44 GPa. In addition, by constructing a photothermal cross-linking network and balancing the proportions of the soft and hard segments, the patterned TCPM can maintain high stability under external stimuli while exhibiting controllable mechanical adaptive behavior owing to its innovative molecular structure. Overall, this unique combination leads to new possibilities for the application of TCPM in fields such as flexible electronics, micro and nanosensing and biomedical engineering.

This review focuses on the recent development of thermally actuated soft robotics, highlighting the four major heating mechanisms, as well as structural designs, thermal management, material innovations, and emerging applications. A summary and outlook section present the current challenges of thermally actuated soft robots and the future directions to address these challenges.

Abstract

Soft robots with exceptional adaptability and versatility have opened new possibilities for applications in complex and dynamic environments. Thermal actuation has emerged as a promising method among various actuation strategieis, offering distinct advantages such as programmability, light weight, low actuation voltage, and untethered operation. This review provides a comprehensive overview of soft thermal actuators, focusing on their heating mechanisms, material innovations, structural designs, and emerging applications. Heat generation mechanisms including Joule heating, electromagnetic induction, and electromagnetic radiation and heat transfer mechanisms such as fluid convection are discussed. Advances in materials are grouped into two areas: heating materials, primarily based on nanomaterials, and thermally responsive materials including hydrogels, liquid crystal elastomers, and shape-memory polymers. Structural designs, such as extension, bending, twisting, and 3D deformable configurations, are explored for enabling complex and precise movements. Applications of soft thermal actuators span environmental exploration, gripping and manipulation, biomedical devices for rehabilitation and surgery, and interactive systems for virtual/augmented reality and therapy. The review concludes with an outlook on challenges and future directions, emphasizing the need for further improvement in speed, energy efficiency, and intelligent soft robotic systems. By bridging fundamental principles with cutting-edge applications, this review aims to inspire further advancements in the field of thermally actuated soft robotics.

Rare-earth Er-MoS₂/Yb-MoS₂ dual-doped homojunction with specific twist angles is reported for the first time and exhibits a threefold PL intensity enhancement with a prolonged exciton lifetime relative to the single doped MoS₂. This unique behavior arises from the formation of localized interlayer excitons induced by two synergistic factors: rare-earth doping modulating effect and specific stacking geometry optimizing interlayer coupling.

Abstract

2D transition metal dichalcogenides (TMDs) have received extensive attention due to their tunable electronic and optical properties. Trivalent rare earth ions doping can be used as luminescence activation centers to significantly improve their luminescence efficiency. Nevertheless, few studies are reported on the investigation of rare-earth dual-doped TMDs homojunctions. Herein, Er-MoS₂/Yb-MoS₂ dual-doped homojunctions with different twist angles are constructed by the mechanically transferred stacking. Unlike pure MoS₂ bilayers or other MoS₂ heterojunctions that suffer from photoluminescence (PL) quenching, the constructed dual-doped MoS₂ homojunctions with specific twist angle exhibit a prominent PL peak with three-fold increase of intensity and prolonged exciton lifetime. This unique behavior arises from the formation of localized interlayer excitons induced by two synergistic factors including rare-earth doping modulating effect and specific stacking angle. The introduction of rare-earth doping increases localized interlayer exciton formation in doped homojunctions and enhances the radiative recombination and exciton lifetimes. The precise control of stacking angles of doped-MoS₂ homojunction can effectively modulate the interlayer coupling, enabling optimized conditions for exciton localization. This work establishes an efficient strategy to construct localized interlayer excitons in rare-earth doped 2D materials for the junctions, but also provides fundamental insights into the design of high-performance light-emitting devices.

Metal halide scintillator, tetraphenylphosphonium manganese bromide (TPP₂MnBr₄), provides a significant benefit for fast neutron imaging. A fourfold increase in efficiency over traditional zinc sulfide screens is achieved by efficiently utilizing neutron interactions within its homogeneous structure. Matching conventional spatial resolution, this development offers shorter exposure times and improved image clarity, broadening the potential applications of fast neutron imaging.

Abstract

Fast neutron imaging is a promising technique for visualizing objects containing dense, mixed light-and-heavy-elements materials, such as combustion engines, nuclear fuel assemblies, and fossils, where X-rays and thermal neutrons are ineffective. However, the limited efficiency of current detection technologies hinders their widespread adoption. Recoil proton detection using two-component scintillator screens composed of doped zinc sulfide (ZnS) microparticles in polypropylene (PP) remains the standard imaging tool due to the high light yield of ZnS. The efficiency is, however, restricted by the low volumetric fraction of ZnS, which cannot be increased without causing excessive light scattering and loss of resolution, while PP is still needed for substantial interaction with neutrons. In this work, a monocompound metal halide tetraphenylphosphonium manganese bromide (TPP₂MnBr₄) scintillator is explored as an alternative, exhibiting 1.5 times higher light output and fourfold higher light yield than conventional ZnS-based scintillators. This improvement arises from superior recoil proton energy utilization in the homogeneous structure of TPP₂MnBr₄ compared to the heterogeneous composition of PP/ZnS. Imaging tests show spatial resolution of around one line pair per millimeter, matching commercial PP/ZnS screens. These results indicate that TPP₂MnBr₄ scintillator can reduce exposure time and improve image quality, paving the way for efficient, high-resolution neutron imaging technologies.

High transparent Sr_0.84Tb_0.16F_2.16 glass-ceramic scintillators possess excellent scintillating performance (XEL intensity is 329% of that of Bi₄Ge₃O₁₂), low detection limit (3.17 µGy_air s⁻¹), high radiation resistance, high spatial resolution (24 lp mm⁻¹) for X-ray imaging, anti-thermal-quenching performance (119% at 393 K), and zero-thermal-quenching performance (100% at 573 K), indicating their excellent applicability for high-temperature X-ray imaging.

Abstract

Glass-ceramic (GC) scintillators, which possess high transparency, outstanding X-ray excited luminescence (XEL) intensity, and excellent thermal stability, have attracted significant attention. In this paper, two strategies, including crystallization of GC and energy transfer from traps, are applied to enhance luminescent performances and thermal stability of glass scintillators. Herein, an optimal sample (GCL-620) with high crystallinity (32.8%) and high transparency (83.1% at 542 nm) is obtained. For photoluminescent performances, GCL-620 exhibits high internal quantum efficiency (92.7%) and excellent thermal stability (99.9% at 573 K). For XEL performances, GCL-620 exhibits high XEL intensity (329% of that of Bi₄Ge₃O₁₂), low detection limit (3.17 µGy_air s⁻¹), and excellent spatial resolution (24 lp mm⁻¹). Besides, anti-thermal-quenching performance (119% at 393 K) and zero-thermal-quenching (100% at 573 K) performance of GCL-620 are both observed in XEL. Imaging clarity of high-temperature X-ray imaging does not decrease with increasing temperature, and the spatial resolution of GCL-620 remains 24 lp mm⁻¹ at high temperature. All results illustrate that Sr_0.84Tb_0.16F_2.16 GC scintillators have a broad prospect in high-temperature X-ray imaging.

The dielectric properties of clays are studied on the level of individual monolayers and functional double stacks. The material breakdown characteristics and charge storage performance are analyzed. For illustration, a defined charge pattern representing a cuneiform character is produced, written into a microscopic clay tile, referencing the origins of the human script.

Abstract

To exploit the full potential of clays for electronic applications, a deeper understanding of how their dielectric properties can be tuned in a defined manner is essential. So far, most attention has been paid to the surface chemistry of clay platelets and their mechanical properties. Important properties, like electrical breakdown voltages, have been studied only on the macroscopic scale and not on the level of single platelets. One open important question that must be addressed is how far the dielectric properties, such as the breakdown characteristics, can be tuned by the composition of the interlayer. By using scanning probe techniques, it became possible to study individual platelets of the synthetic hectorite. Their interlayer composition is varied by encapsulating different cations between the silicate monolayers, besides sodium, ammonium, and an organic dye. The electrical breakdown characteristics of the monolayers and functional double stacks of hectorite are determined at the single platelet level. The use of these clay-based materials as electrets is evaluated by creating defined charge patterns at the nm-level and recording their isothermal potential decay. Thereby, the charge retention properties of the different clay compounds are determined.

Nature Materials, Published online: 09 July 2025; doi:10.1038/s41563-025-02263-1

An inverse design strategy is reported for the organization of nanoscale matter using DNA-programmable bonds and the fabrication of hierarchically ordered 3D assemblies.

Nature Materials, Published online: 09 July 2025; doi:10.1038/s41563-025-02262-2

Harnessing DNA-programmable bonds through inverse design, nanoparticles are directed to self-assemble into hierarchically ordered three-dimensional architectures, enabling the nanofabrication of complex, multifunctional materials.

Atomically precise bimetallic nanoclusters (BNCs) feature a new generation of metal nanomaterials, but BNCs-mediated photocatalysis has still been in the infant stage. In this review, the types is overviewed, preparation and characterization methods of atomically precise BNCs, and moreover up-to-date exciting research progress on the multifarious applications of BNCs in the fields of heterogeneous photocatalysis are concisely reviewed paired with insightful discussion on photocatalytic mechanisms of BNCs artificial photosystems. Finally, future prospects and challenges in this booming research field are outlooked.

Abstract

Atomically precise metal nanoclusters (NCs) demonstrate the unprecedented merits including unique atomic stacking pattern, quantum confinement effect, abundant active sites, and discrete energy band structure, filling the gap between single atoms and conventional metal nanocrystals. Integrating two metals into one nanocluster unit to craft bimetallic NCs (BNCs) significantly endow metal NCs with fascinating physicochemical properties, electronic structures, and metal-ligand interaction mechanisms through the bimetallic cooperative synergy. Nevertheless, there has still been a lack of comprehensive, insightful and timely overview on BNCs-based photoredox catalysis. Herein, this review recaps the category, synthetic strategies and characterization methods of a new generation of atomically precise BNCs, along with their recent exciting cutting-edge progress in diverse photoredox catalysis, including photocatalytic hydrogen production, CO₂ reduction, selective organic transformation and environmental remediation. The charge transfer mechanisms and insight into structure-activity correlation in different redox catalysis reactions are elucidated. Eventually, future prospects and challenging tasks in this booming research field are discussed. The current review is expected to timely provide an emerging roadmap for customizing novel BNCs as a versatile photocatalyst platform toward solar energy conversion.

Nature, Published online: 09 July 2025; doi:10.1038/s41586-025-09187-5

A new class of moiré materials based on monolayers with triangular lattices and low-energy states at the M points of the Brillouin zone is introduced, demonstrating emergent momentum-space non-symmorphic symmetries, a kagome plane-wave lattice structure, and potential quasi-one-dimensionality.

Herein, direct laser writing is used to polymerize self-assembled nanocomposite materials. Using fabrication parameters, the interparticle spacing is finely tuned beyond the thermodynamically stable state. This is exploited to generate wide gamut structural color in water. Numerical simulations are used to support this, to enable the use of scattering spectra to predict volume fraction and interparticle spacing on the nanoscale.

Abstract

Self-assembled colloidal particles offer a means of manipulating light, giving rise to some of the most brilliant structural colors. Conventionally, changing the reflection band of colloidal crystal assemblies has required the synthesis of different-sized nanoparticles or multiple fabrication steps. This is not a means conducive to fine-tuning structural color. Herein, it is shown that, by combining nanocomposite photoresists, self-assembly, and direct laser writing, it is possible to achieve high-resolution fabrication and precise placement of nanoparticles, combined with highly tunable structural color using one composition and one particle size. Confinement of polymerization brought by direct laser writing allows for fine control over a series of fabrication parameters, such as slicing and hatching distances, thereby enabling control of the inter-particle distance in a nanocomposite. This is key to generating microstructures that exhibit a wide gamut of color that traverses the visible spectrum. Finite-difference time-domain simulations are further used as a means of understanding the structural modifications that control color variation. The method described herein is suitable for fine-tuning of structural color in self-assembled systems, and is applicable to a wide range of materials.

Focused electron beam induced etching (FEBIE) with a XeF₂ (xenon difluoride) precursor is conducted on exfoliated WS₂ (tungsten disulfide) and monolayer WS₂ grown by chemical vapor deposition to calculate etch rates and efficiencies as a function of electron beam energy, current, dwell time, and XeF₂ pressure. The etched films are characterized by atomic force microscopy and Raman and photoluminescence spectroscopy which measured little damage.

Abstract

Focused electron beam induced etching (FEBIE) with XeF₂ (xenon difluoride) precursor is conducted on multi-layer exfoliated WS₂ (tungsten disulfide) and monolayer WS₂ grown by chemical vapor deposition (CVD). The films are characterized by atomic force microscopy (AFM) and Raman and photoluminescence (PL) spectroscopy post-etching. The etch rates/efficiencies are reported as a function of electron beam energy, current, dwell time, and XeF₂ pressure. Bulk film Raman spectra are unchanged post-FEBIE, indicating minimal subsurface damage. Monolayer WS₂ shows a decrease in Raman and PL intensity post-FEBIE, with a dose-to-clear of ≈2 nC µm⁻². The study reveals regimes affected by the various mass transport contributions such as refresh time and the ratio of electrons/XeF₂. Spontaneous etching was discovered during FEBIE of large patterned areas due to the long frame/refresh times. Density functional theory and ab initio molecular dynamics simulations compares desorption of SF_x and WF_x molecules from pristine WS₂ basal planes and pore edges, revealing the spontaneous etching is consistent with etching of partially etched monolayers during each frame. Single-line etching width of 21 nm, and patterning flakes into 100 nm wide channels are demonstrated. This work demonstrates the possibility of editing WS₂ flakes into electronic devices of arbitrary dimensions for semiconductor applications.

Europium ions reversibly intercalate into the van der Waals gap of bilayer graphene when heat and electrostatic gate act together, switching the stacking order and electronic response on demand. Real-time transport, simulations, and device tests expose a hidden 2D Eu sheet and its temperature-tuned diffusion, showing a versatile electrochemical route toward reconfigurable 2D heterostructures with rare-earth functionality.

Abstract

Atomic-scale control and understanding the controlling strategy of ion intercalation are pivotal for advancing energy storage, quantum technologies, and adaptive electronics. While intercalation – the insertion of ions into layered materials – has transformative potential, the mechanisms driving it, particularly for rare-earth ions, remain poorly understood. Here, a thermal-electrostatic strategy is developed to achieve reversible and tunable europium ion intercalation that enables precise control over intercalation dynamics. This study investigates how temperature and voltage influence the intercalation of europium ions into bilayer graphene. Our results reveal the formation of a 2D europium layer and ionic state of intercalation europium within the graphene structure, providing fundamental insights into intercalation energetics. This work establishes a versatile platform for designing adaptive 2D heterostructure, engineering advanced materials and devices with unique electronic and optoelectronic properties.

Nature Communications, Published online: 06 July 2025; doi:10.1038/s41467-025-61522-6

The authors propose a set of guidelines for far-UVC optical design, under which the multi-stimulated far-UVC luminescence at 222 nm in Pr3+ -doped SrF2 is realized, offering unique opportunities for solar-blind imaging and structural health monitoring in complex environments.

Nature Photonics, Published online: 03 July 2025; doi:10.1038/s41566-025-01705-1

Holmium-doped nanoparticles exhibit a novel parallel photon avalanching mechanism, offering controlled chromaticity and enabling sub-diffraction, multicolour bio-imaging upon excitation with a single near-infrared laser.

A self-evolving discovery integrating automation and AI is developed to address the high-dimensional-parameter-space challenge in carrier biomaterials. The discovered biomaterials showed ultra-low nonspecific protein adsorption, achieving a 10 000-fold reduction in experiment workload; and they are further fabricated into microfluidic-used carriers for protein-analysis applications, showing a 9-fold enhancement in detection sensitivity. This study has potential for applications in single-cell analysis.

Abstract

Carrier biomaterials used in single-cell analysis face a bottleneck in protein detection sensitivity, primarily attributed to elevated false positives caused by nonspecific protein adsorption. Toward carrier biomaterials with ultra-low nonspecific protein adsorption, a self-evolving discovery is developed to address the challenge of high-dimensional parameter spaces. Automation across nine self-developed or modified workstations is integrated to achieve a “can-do” capability, and develop a synergy-enhanced Bayesian optimization algorithm as the artificial intelligence brain to enable a “can-think” capability for small-data problems inherent to time-consuming biological experiments, thereby establishing a self-evolving discovery for carrier biomaterials. Through this approach, carrier biomaterials with an ultra-low nonspecific protein adsorption index of 0.2537 are successfully discovered, representing an over 80% decrease, while achieving a 10 000-fold reduction in experiment workload. Furthermore, the discovered biomaterials are fabricated into microfluidic-used carriers for protein-analysis applications, showing a 9-fold enhancement in detection sensitivity compared to conventional carriers. This is the very demonstration of a self-evolving discovery for carrier biomaterials, paving the way for advancements in single-cell protein analysis and further its integration with genomics and transcriptomics.

This study utilizes single particle tracking (SPT) to capture real-time interactions between DNA origami nanorods (NRs) and cell surfaces. Functionalized NRs targeting EGFR-expressing cells exhibit selective binding, while nonfunctionalized NRs show minimal interaction. SPT data reveal distinct binding dynamics influenced by ligand type and density, offering new insights into DNA origami behavior at the cell interface for biomedical applications.

Abstract

Due to the unique spatial addressability of DNA origami, targeting ligands can be specifically positioned onto the surface of the nanostructure, constituting an essential tool for studying ligand-receptor interactions at the cell surface. While the design and ligand incorporation into DNA origami nanostructures is well-established, the study of dynamic interactions with cell surfaces is still in the explorative phase, where an in-depth fundamental understanding of the molecular interaction dynamics remains underexplored. This study uniquely captures real-time encounters between DNA origami and cells in situ using single particle tracking (SPT). We functionalized DNA nanorods (NRs) with antibodies or aptamers specific to the epidermal growth factor receptor (EGFR) and used them to target EGFR-overexpressing cells. SPT data revealed that ligand-coated NRs selectively bind to the receptors expressed in target cancer cells, while non functionalized NRs only display negligible cell interactions. Furthermore, the effect of ligand density is explored on the DNA origami, which revealed that aptamer-decorated NRs exhibit nonlinear binding characteristics, whereas this effect in antibody-decorated NRs is less pronounced. This study provides new mechanistic insights into the fundamental understanding of DNA origami behavior at the cell interface, with unprecedented spatiotemporal resolution, aiding the rational design of ligand-targeted DNA origami for biomedical applications.

Nature Electronics, Published online: 01 July 2025; doi:10.1038/s41928-025-01408-z

A three-dimensional metal stamp can be used to selectively exfoliate two-dimensional materials, allowing the remaining material to be patterned into two-dimensional arrays without leaving chemical or polymer residues.

This work demonstrates antiferromagnetic interfacial coupling in EuO/KTaO₃ heterostructures enabled by LaTiO₃ buffer layers. Polarized neutron reflectometry reveals proximity-induced antiparallel alignment between EuO and interfacial KTaO₃ across the LaTiO₃ spacer, and transport measurements indicate spin-polarized two-dimensional electron gases. Density functional theory further supports the antiferromagnetic interfacial coupling. These findings highlight interface engineering as a powerful tool for tailoring magnetic interactions.

Abstract

Artificial oxide heterostructures provide valuable opportunities for tailoring interfacial magnetic coupling, which is a central topic of spintronics. In this work, the antiferromagnetic interfacial magnetic coupling is demonstrated in EuO/KTaO₃ (001) heterostructures by introducing a LaTiO₃ (LTO) buffer layer. Depth-resolved polarized neutron reflectometry reveals that ferromagnetic EuO induces magnetism in the adjacent LTO buffer layer and the interfacial KTaO₃ (KTO) through the magnetic proximity effect (MPE). Remarkably, the introduction of the LTO buffer layer at the EuO/KTO interface results in antiparallel alignment between the interfacial KTO layer and EuO, indicating proximity-induced antiferromagnetic coupling across the spacer layer. Anomalous Hall effect and hysteretic magnetoresistance measurements indicate the presence of spin-polarized 2D electron gases in the interfacial layer of KTO. The maximum thickness of the LTO buffer layer for EuO to be able to magnetize KTO is 8 uc (≈3.2 nm), beyond which no hysteretic magnetoresistance is observed. Density functional theory calculations suggest that antiferromagnetic coupling lowers the system energy in LTO-buffered EuO/KTO heterostructure, corroborating the experimental findings. This work highlights the crucial role of interface engineering in controlling interfacial magnetic coupling, providing novel pathways for designing advanced spintronic devices.