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1.
Nano Lett ; 24(2): 733-740, 2024 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-38166427

RESUMO

The Hall effect has played a vital role in unraveling the intricate properties of electron transport in solid materials. Here, we report on a crystal symmetry-dependent in-plane Hall effect (CIHE) observed in a CuPt/CoPt ferromagnetic heterostructure. Unlike the planar Hall effect (PHE), the CIHE in CuPt/CoPt strongly depends on the current flowing direction (ϕI) with respect to the crystal structure. It reaches its maximum when the current is applied along the low crystal-symmetry axes and vanishes when applied along the high crystal-symmetry axes, exhibiting an unconventional angular dependence of cos(3ϕI). Utilizing a symmetry analysis based on the Invariant Theory, we demonstrate that the CIHE can exist in magnetic crystals possessing C3v symmetry. Using a tight-binding model and realistic first-principles calculations on the metallic heterostructure, we find that the CIHE originates from the trigonal warping of the Fermi surface. Our observations highlight the critical role of crystal symmetry in generating new types of Hall effects.

2.
Small ; : e2403073, 2024 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-38966892

RESUMO

Spin injection, transport, and detection across the interface between a ferromagnet and a spin-carrying channel are crucial for energy-efficient spin logic devices. However, interfacial conductance mismatch, spin dephasing, and inefficient spin-to-charge conversion significantly reduce the efficiency of these processes. In this study, it is demonstrated that an all van der Waals heterostructure consisting of a ferromagnet (Fe3GeTe2) and Weyl semimetal enables a large spin readout efficiency. Specifically, a nonlocal spin readout signal of 150 mΩ and a local spin readout signal of 7.8 Ω is achieved, which reach the signal level useful for practical spintronic devices. The remarkable spin readout signal is attributed to suppressed spin dephasing channels at the vdW interfaces, long spin diffusion, and efficient charge-spin interconversion in Td-MoTe2. These findings highlight the potential of vdW heterostructures for spin Hall effect-enabled spin detection with high efficiency, opening up new possibilities for spin-orbit logic devices using vdW interfaces.

3.
Nano Lett ; 23(14): 6378-6385, 2023 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-37418477

RESUMO

Unidirectional magnetoresistance (UMR) has been intensively studied in ferromagnetic systems, which is mainly induced by spin-dependent and spin-flip electron scattering. Yet, UMR in antiferromagnetic (AFM) systems has not been fully understood to date. In this work, we reported UMR in a YFeO3/Pt heterostructure where YFeO3 is a typical AFM insulator. Magnetic-field dependence and temperature dependence of transport measurements indicate that magnon dynamics and interfacial Rashba splitting are two individual origins for AFM UMR, which is consistent with the UMR theory in ferromagnetic systems. We further established a comprehensive theoretical model that incorporates micromagnetic simulation, density functional theory calculation, and the tight-binding model, which explain the observed AFM UMR phenomenon well. Our work sheds light on the intrinsic transport property of the AFM system and may facilitate the development of AFM spintronic devices.

4.
Small ; 19(21): e2208157, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36808873

RESUMO

Anti-dehydration hydrogels have attracted considerable attention due to their promising applications in stretchable sensors, flexible electronics, and soft robots. However, anti-dehydration hydrogels prepared by conventional strategies inevitably depend on additional chemicals or suffer from cumbersome preparation processes. Here, inspired by the succulent Fenestraria aurantiaca a one-step wetting-enabled three-dimensional interfacial polymerization (WET-DIP) strategy for constructing organogel-sealed anti-dehydration hydrogels is developed. By virtue of the preferential wetting on the hydrophobic-oleophilic substrate surfaces, the organogel precursor solution can spread on the three-dimensional (3D) surface and encapsulate the hydrogel precursor solution, forming anti-dehydration hydrogel with 3D shape after in situ interfacial polymerization. The WET-DIP strategy is simple and ingenious, and accessible to discretionary 3D-shaped anti-dehydration hydrogels with a controllable thickness of the organogel outer layer. Strain sensors based on this anti-dehydration hydrogel also exhibit long-term stability in signal monitoring. This WET-DIP strategy shows great potentialities for constructing hydrogel-based devices with long-term stability.

5.
Small ; 16(4): e1905902, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31867892

RESUMO

Semiconducting nanowires offer many opportunities for electronic and optoelectronic device applications due to their unique geometries and physical properties. However, it is challenging to synthesize semiconducting nanowires directly on a SiO2 /Si substrate due to lattice mismatch. Here, a catalysis-free approach is developed to achieve direct synthesis of long and straight InSe nanowires on SiO2 /Si substrates through edge-homoepitaxial growth. Parallel InSe nanowires are achieved further on SiO2 /Si substrates through controlling growth conditions. The underlying growth mechanism is attributed to a selenium self-driven vapor-liquid-solid process, which is distinct from the conventional metal-catalytic vapor-liquid-solid method widely used for growing Si and III-V nanowires. Furthermore, it is demonstrated that the as-grown InSe nanowire-based visible light photodetector simultaneously possesses an extraordinary photoresponsivity of 271 A W-1 , ultrahigh detectivity of 1.57 × 1014 Jones, and a fast response speed of microsecond scale. The excellent performance of the photodetector indicates that as-grown InSe nanowires are promising in future optoelectronic applications. More importantly, the proposed edge-homoepitaxial approach may open up a novel avenue for direct synthesis of semiconducting nanowire arrays on SiO2 /Si substrates.

6.
Adv Mater ; : e2401021, 2024 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-38695721

RESUMO

Brain-inspired neuromorphic computing has attracted widespread attention owing to its ability to perform parallel and energy-efficient computation. However, the synaptic weight of amorphous/polycrystalline oxide based memristor usually exhibits large nonlinear behavior with high asymmetry, which aggravates the complexity of peripheral circuit system. Controllable growth of conductive filaments is highly demanded for achieving the highly linear conductance modulation. However, the stochastic behavior of the filament growth in commonly used amorphous/polycrystalline oxide memristor makes it very challenging. Here, the epitaxially grown Hf0.5Zr0.5O2-based memristor with the linearity and symmetry approaching ideal case is reported. A layer of Cu nanoparticles is inserted into epitaxially grown Hf0.5Zr0.5O2 film to form the grain boundaries due to the breaking of the epitaxial growth. By combining with the local electric field enhancement, the growth of filament is confined in the grain boundaries due to the fact that the diffusion of oxygen vacancy in crystalline lattice is more difficult than that in the grain boundaries. Furthermore, the decimal operation and high-accuracy neural network are demonstrated by utilizing the highly linear and multi-level conductance modulation capacity. This method opens an avenue to control the filament growth for the application of resistance random access memory (RRAM) and neuromorphic computing.

7.
ACS Appl Mater Interfaces ; 16(1): 1129-1136, 2024 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-38118124

RESUMO

Materials with strong spin-orbit coupling (SOC) have been continuously attracting intensive attention due to their promising application in energy-efficient, high-density, and nonvolatile spintronic devices. Particularly, transition-metal perovskite oxides with strong SOC have been demonstrated to exhibit efficient charge-spin interconversion. In this study, we systematically investigated the impact of epitaxial strain on the spin-orbit torque (SOT) efficiency in the SrIrO3(SIO)/Ni81Fe19(Py) bilayer. The results reveal that the SOT efficiency is strongly related to the octahedral rotation around the in-plane axes of the single-crystal SIO. By modulating the epitaxial strain using different substrates, the SOT efficiency can be remarkably improved from 0.15 to 1.45. This 10-fold enhancement of SOT efficiency suggests that modulating the epitaxial strain is an efficient approach to control the SOT efficiency in complex oxide-based heterostructures. Our work may have the potential to advance the application of complex oxides in energy-efficient spintronic devices.

8.
Nat Commun ; 15(1): 745, 2024 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-38272914

RESUMO

The electrical control of the non-trivial topology in Weyl antiferromagnets is of great interest for the development of next-generation spintronic devices. Recent studies suggest that the spin Hall effect can switch the topological antiferromagnetic order. However, the switching efficiency remains relatively low. Here, we demonstrate the effective manipulation of antiferromagnetic order in the Weyl semimetal Mn3Sn using orbital torques originating from either metal Mn or oxide CuOx. Although Mn3Sn can convert orbital current to spin current on its own, we find that inserting a heavy metal layer, such as Pt, of appropriate thickness can effectively reduce the critical switching current density by one order of magnitude. In addition, we show that the memristor-like switching behaviour of Mn3Sn can mimic the potentiation and depression processes of a synapse with high linearity-which may be beneficial for constructing accurate artificial neural networks. Our work paves a way for manipulating the topological antiferromagnetic order and may inspire more high-performance antiferromagnetic functional devices.

9.
Hum Vaccin Immunother ; 19(1): 2211896, 2023 12 31.
Artigo em Inglês | MEDLINE | ID: mdl-37249318

RESUMO

This phase III clinical trial aimed to assess the safety and demonstrate the immunogenicity of a candidate freeze-dried purified Vero cell-based rabies vaccine (PVRV-WIBP) developed for human use. A cohort of 40 participants in stage 1 and 1956 subjects in stage 2 with an age range of 10-50 years were recruited for the phase III clinical trial. For safety analysis in stage 1, 20 participants received either 4-dose or 5-dose regimen of PVRV-WIBP. In stage 2, 1956 subjects were randomly divided into the 5-dose PVRV-WIBP, 5-dose PVRV-LNCD, and 4-dose PVRV-WIBP groups. The serum neutralizing antibody titer against rabies was determined on day 7 or 14 and day 35 or 42. Adverse reactions were recorded for more than 6 months. Most adverse reactions, which were mild and moderate in severity, occurred and resolved within 1 week after each injection in the PVRV-WIBP (4 and 5 doses) and PVRV-LNCD (5 doses) groups. All three groups achieved complete seroconversion 14 days after the initial dose and 14 days after completing the full vaccination schedule, the susceptible subjects in the PVRV-WIBP group (4-dose or 5-dose regimen) displayed higher neutralizing antibody titers against the rabies virus compared to those in the PVRV-LNCD group (5-dose regimen). PVRV-WIBP induced non-inferior immune responses versus PVRV-LNCD as assessed by seroconversion rate. PVRV-WIBP was well tolerated and non-inferior to PVRV-LNCD in healthy individuals aged 10-50 years. The results indicated that PVRV-WIBP (both 4- and 5-dose schedules) could be an alternative to rabies post-exposure prophylaxis.


Assuntos
Soropositividade para HIV , Vacina Antirrábica , Vírus da Raiva , Raiva , Animais , Chlorocebus aethiops , Humanos , Criança , Adolescente , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Raiva/prevenção & controle , População do Leste Asiático , Anticorpos Antivirais , Anticorpos Neutralizantes , Células Vero , Imunogenicidade da Vacina
10.
Adv Mater ; 34(16): e2110408, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35180331

RESUMO

Underwater superoleophobic surfaces featuring anti-oil-fouling properties are of great significance in widespread fields. However, their complicated engineering process and weak interfacial adhesion strength with underlying substrates severely hamper these ideal surfaces toward practical applications. Here, a moss-inspired sticky-slippy skin composed of layered organohydrogel is reported through a one-step wetting-enabled-transfer (WET) strategy, which unprecedentedly integrates robust inherent adhesion with durable anti-oil-fouling properties. The sticky organogel layer can be simply attached to various substrates, from metals and plastics to glass, independent of any surface pretreatment. The slippy hydrogel layer enables stable underwater superoleophobicity and ultralow oil adhesion for diverse kinds of oils. The sticky-slippy skin features outstanding comprehensive properties including easy-pasting, anti-swelling/anti-bending, compatibility with commercial adhesives, acid/alkali resistance, environmental friendliness, and substrate universality. The design strategy with integrated functions provides a clue to accelerate the development of bioinspired multifunctional interfacial materials toward real-world applications.


Assuntos
Materiais Biomiméticos , Água , Óleos/química , Fenômenos Físicos , Água/química , Molhabilidade
11.
Front Bioeng Biotechnol ; 10: 1072393, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36452209

RESUMO

Stimulating immunogenic cell death (ICD) is the key to tumor immunotherapy. However, traditional chemoradiotherapy has limited effect on stimulating immunity and often requires repeated administration, which greatly reduces the tumor-killing effect. In this article, we created a sodium alginate hydrogel sustained-release system containing low-dose doxorubicin (Dox) and immune adjuvant R837, which were injected into the interstitial space to wrap around the tumor in situ, achieving a sustained release and long-lasting immune response. Cooperating with immune checkpoint blockade, Dox induced ICD, activated dendritic cells (DCs) and converted immunosuppressive M2-type tumor-associated macrophages (TAM) to tumor-killing M1-type TAMs. Simultaneously, it greatly promoted T cell proliferation and infiltration, and reduced tumor immunosuppressive factors, triggering a robust immune response to suppress tumors in vivo. In conclusion, this anti-tumor strategy based on interstitial injection can achieve continuous local immune stimulation by low-dose chemotherapy drugs, providing a potential approach for tumor immunotherapy.

12.
Adv Mater ; 33(16): e2008557, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33709446

RESUMO

The ability to manipulate water and oil phases in a designable manner is of great significance in widespread fields from art paintings to materials science. However, achieving precise and stable surface patterns for two immiscible phases of water and oil remains a challenge. Herein, a general wetting-enabled-transfer (WET) strategy is reported to construct discretionary shape-defined surface patterns of organohydrogels along with their monolithic formation either from flat to curved surfaces or from the microscale to the macroscale. Locally differentiated wettability induces hydrophilic monomers and hydrophobic monomers from an emulsion system onto the wettability-matching regions of the prepatterned substrates, subsequently forming corresponding hydrogel and organogel patterns on the organohydrogel surface after in situ photopolymerization. The precision of the surface patterns can be controlled by optimizing the gel monomers, emulsion droplet size, and surface chemical composition of the prepatterned substrates. This finding may provide a feasible strategy for precisely patterning functional materials from two-immiscible-phase systems.

13.
ACS Nano ; 14(7): 8449-8458, 2020 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-32538617

RESUMO

The inspection of Friedel's law in ultrafast electron diffraction (UED) is important to gain a comprehensive understanding of material atomic structure and its dynamic response. Here, monoclinic gallium telluride (GaTe), as a low-symmetry, layered crystal in contrast to many other 2D materials, is investigated by mega-electronvolt UED. Strong out-of-phase oscillations of Bragg peak intensities are observed for Friedel pairs, which does not obey Friedel's law. As evidenced by the preserved mirror symmetry and supported by both kinematic and dynamic scattering simulations, the intensity oscillations are provoked by the lowest-order longitudinal acoustic breathing phonon. Our results provide a generalized understanding of Friedel's law in UED and demonstrate that by designed misalignment of surface normal and primitive lattice vectors, coherent lattice wobbling and effective shear strain can be generated in crystal films by laser pulse excitation, which is otherwise hard to achieve and can be further utilized to dynamically tune and switch material properties.

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