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Spin injection stands out as a crucial method employed for initializing, manipulating, and measuring the spin states of electrons, which are fundamental to the creation of qubits in quantum computing. However, ensuring efficient spin injection while maintaining compatibility with standard semiconductor processing techniques is a significant challenge. Herein, we demonstrate the capability of inducing an ultrafast spin injection into a WSe2layer from a magnetic CrI3layer on a femtosecond time scale, achieved through real-time time-dependent density functional theory calculations upon a laser pulse. Following the peak of the magnetic moment in the CrI3sublayer, the magnetic moment of the WSe2layer reaches a maximum of 0.89 µB(per unit cell containing 4 WSe2and 1 CrI3units). During the spin dynamics, spin-polarized excited electrons transfer from the WSe2layer to the CrI3layer via type-II band alignment. The large spin splitting in conduction bands and the difference in the number of spin-polarized local unoccupied states available in the CrI3layer lead to a net spin in the WSe2layer. Furthermore, we confirmed that the number of available states, the spin-flip process, and the laser pulse parameters play important roles during the spin injection process. This work highlights the dynamic and rapid nature of spin manipulation in layered all-semiconductor systems, offering significant implications for the development and enhancement of quantum information processing technologies.

Freestanding thin films of functional materials enable the tuning of properties via strain and strain gradients, broadening their applications. Here, a systematic approach is proposed to fabricate freestanding CrMnFeCoNi high-entropy alloy (HEA) thin films by pulsed laser deposition using expansion-contraction of NaCl substrates and weak van der Waals interaction of the interface, which form wrinkles with inhomogeneous strain gradients when transferred to a viscous handle. We demonstrate that the nonuniform gradients of external strain (flexomagnetic effect) can induce the partial structural phase transition from FCC to BCC in the wrinkled HEA film, resulting in a 10-fold increase in its room-temperature saturation magnetization compared with the unstrained flat HEA film. Furthermore, after applying an external magnetic field, due to the different electron transfer behavior caused by the electron scattering in wrinkled and flat HEA films, their electrocatalytic magnetic responses showed a diametrically opposite picture. Our work provides a promising strategy for tuning physical and chemical properties via complex strained geometries.

The cancer-associated fibroblast (CAF) barrier in pancreatic ductal adenocarcinoma (PDAC) greatly restricts clinical outcomes. Major obstacles to PDAC treatment include restricted immune cell infiltration and drug penetration and the immunosuppressive microenvironment. Here, we reported a “shooting fish in a barrel” strategy by preparing a lipid–polymer hybrid drug delivery system (PI/JGC/L-A) that could overcome the CAF barrier by turning it into a “barrel” with antitumor drug depot properties to alleviate the immunosuppressive microenvironment and increase immune cell infiltration. PI/JGC/L-A is composed of a pIL-12-loaded polymeric core (PI) and a JQ1 and gemcitabine elaidate coloaded liposomal shell (JGC/L-A) that has the ability to stimulate exosome secretion. By normalizing the CAF barrier to create a CAF “barrel” with JQ1, stimulating the secretion of gemcitabine-loaded exosomes from the CAF “barrel” to the deep tumor site, and leveraging the CAF “barrel” to secrete IL-12, PI/JGC/L-A realized effective drug delivery to the deep tumor site, activated antitumor immunity at the tumor site, and produced significant antitumor effects. In summary, our strategy of transforming the CAF barrier into antitumor drug depots represents a promising strategy against PDAC and might benefit the treatment of any tumors facing a drug delivery barrier.

Multiferroic materials with tunable magnetoelectric orders enable the integration of sensing, data storage, and processing into one single device. The scarcity of single-phase multiferroics spurs extensive research in pursuit of composite systems combining different types of ferroic materials. In this work, spin-constrained photoelectric memory is proposed in two-dimensional (2D) layered magnetic/ferroelectric heterostructures, holding the possibility of low-power electrical write operation and nondestructive optical read operation. The ground state of ferromagnetic (FM) and antiferromagnetic (AFM) orderings in the magnetic layer is altered by polarization direction of the ferroelectric layer. Specifically, the FM heterostructure exhibits a type-II band alignment. Due to the light-induced charge transfer, spin-polarized/unpolarized current arises from the FM/AFM state, which can be recorded as the “1”/“0” state and served for logic processing and memory applications. Our first-principles calculations demonstrate that the NiI2/In2Se3heterobilayer is an ideal candidate to realize such a spin-dependent photoelectric memory. The reversible FM state (easy-axis magnetic anisotropy) and AFM state (easy-plane magnetic orientation) in the NiI2layer originate from interfacial charge transfer and effective electric field due to the proximity effect. This work offers considerable potential in the integration of memory processing capability into one single device with 2D layered multiferroic heterostructures.

With the assistance of a magnetic field, Hsyn, a series of Zn0.15Fe2.85O4(ZFO) nanoparticle chains (NCs) with a mean particle diameter of around ∼140 nm and different chain lengths are synthesized by mild oxidation of ferrous hydroxide gel. The Mössbauer spectra demonstrated that Zn ions were incorporated into the tetrahedral sites of the spinel structure. The remarkable influence of the increasing Hsynon the growth of ZFO NCs is found not only in the increased length of the assembled particle chain but also in the improved crystallinity evidenced by the increased size of crystalline grains from 18 to 44 nm. The observed monotonous enhancement of saturation magnetization with increasing Hsynis in perfect accordance with that of the relative absorption intensity ratio B/A determined by Mössbauer spectra, suggesting that the difference in the overall number of Fe ions between B and A sites is the main contribution to the magnetization owing to the weakening of the antiferromagnetic interaction among these two sites. Combined with ferromagnetic resonance, magnetic anisotropy of the grown ZFO NCs is found to strongly depend on the demagnetizing field associated with the elongated chain shape.

Two-dimensional (2D) van der Waals (vdW) engineering has brought about many extraordinary and new physics concepts and potential applications. Herein, we propose a new type of spin-constrained optoelectronic device developed using 2D ferromagnetic semiconductor heterostructures (FMSs). It is based on a photoexcited double-band-edge transition model, involved coupling between the interlayer magnetic order and the spin-polarized band structure and can achieve the reversible switch of band alignment viareversal of magnetization. We demonstrate that such a unique magnetic optoelectronic device can be realized with a CrBr3/CrCl3heterojunction and other 2D FMS heterojunctions that have the same direction as the easy magnetization axis and have a switchable band alignment that allows reconfiguration. This study opens a new application window for 2D vdW heterostructures and enables the possibility for fully vdW-based ultra-compact spintronics devices.

In the present work, we optimized the ultrasound-assisted extraction condition of antioxidative substances from Rheum officinaleby orthogonal experiment followed by response surface methodology. The obtained ethanol extract of R. officinale(EER) was further investigated with its antioxidant activity, the effect on extending the longevity of Drosophila melanogasterand antibacterial activity against Propionibacterium acnes.The results showed that the EER extracted under the condition of solid–liquid ratio of 1:43, ultrasonic extraction time of 8 min and ethanol concentration of 50% got the highest radical scavenging (92.95 ± 1.82%), whose antioxidant activity was close to ascorbic acid and butylated hydroxytoluene. In Longevity assay, male flies were fed extract with a range from 50 to 200 mg/L and the result showed a good work on extending the lifespan of fruit flies. In antibacterial assays, the EER exhibited a moderate antibacterial ability. Moreover, it is found that Rhein could be the main constituent against Propionibacterium acnes. Therefore, R. officinalecould be developed continuously for application in medical, cosmetic and anti-aging field, due to its potential antioxidant, anti-P. acnesand anti-aging activities.

Two-dimensional (2D) ferromagnetic semiconductors (FMSs) exhibit novel spin-dependent electronic and optical properties, opening up exciting opportunities for nanoscale spintronic devices. However, experimentally confirmed 2D FMSs based on transition metal ions are rather limited and their performances are not satisfactory, e.g.typically with low Curie temperatures and small magnetic signals. Different from most known 2D magnets based on d-electrons, here an exotic 2D FMS based on rare-earth ions with f-electrons, a GdI2monolayer, is predicted to have a large magnetization (8 μBf.u.−1), whose ferromagnetism can survive near room temperature (241 K). In addition, with a small exfoliation energy from its layered van der Waals (vdW) bulk, this GdI2monolayer holds excellent dynamical and thermal stabilities, making our prediction promising in experiments. Our prediction not only offers a compelling FMS for spintronics, but also provides an alternative route to acquire more high-performance 2D FMSs, going beyond pure d-electron compounds.

By means of first-principles calculations, we investigated the geometric structure, dynamic and thermal stabilities, and electronic properties of the two-dimensional (2D) Janus group III chalcogenide monolayer MoTeB2. The MoTeB2monolayer exhibits a stable sandwiched structure, and its semimetal electronic structure features the perfect electron–hole compensation. The 1:1 electron–hole carrier ratio and high carrier mobility endow the MoTeB2monolayer with large and nonsaturating magnetoresistance. Its electronic properties are easily adjustable by minute charge doping and small tensile stains; in particular, the switch of carrier polarity and metal–semiconductor phase transformation can be achieved. This study not only leads to the finding of the Janus MoTeB2monolayer as a promising 2D material with extraordinary magnetoresistance but also provides a general route to adjust the magnetoresistance effect by compressive stain and charge doping.

The structural, electronic, and magnetic properties of two kinds of boron-doped europium cyclooctatetraene sandwich molecular wires (SMWs), [EuCOTB]∞and [Eu-COTB-Eu-COT]∞(Eu = europium, COT = cyclooctatetraene = C8H8, COTB = boratacyclooctatetraene), are investigated with spin-polarized density functional theory. Both SMWs are of high stability and ultrahigh magnetic moments, and the [Eu-COTB-Eu-COT]∞SMW even owns half-metallic characteristics. Our calculations further reveal that the [Eu-COTB-Eu-COT]∞SMW anchored on a semiconductor germanium surface is a quasi-half-metallic ferromagnet, and it can be tuned into full half-metallicity under a mild external electric field. The unveiled intriguing properties here suggest that the boron-doped europium cyclooctatetraene SMWs may be compelling candidates for future spintronics devices.

Synthesis of two-dimensional (2D) metal chalcogenide based half-metallic nanosheets is in high demand for modern electronics and spintronics applications. Herein, we predict from first-principles calculations that the 2D heterostructure Co/MoS2, consisting of a monolayer of Co atoms deposited on a single MoS2sheet, possesses robust ferromagnetic and half-metallic features and exhibits 100% spin-filter efficiency within a broad bias range. Its ferromagnetic and half-metallic nature persists even when overlaid with a graphene sheet. Because of the relatively strong surface binding energy and low clustering ratio of Co atoms on the MoS2surface, we predict that the heterostructure is synthesizable via wetting deposition of Co on MoS2by electron-beam evaporation technique. Our work strongly suggests Co/MoS2as a compelling and feasible candidate for highly effective information and high-density memory devices.

Synthesizing large-area high-quality graphene at low temperature is crucial for graphene applications in electronics and spintronics. In this work, we demonstrate that adsorption of a single active metal atom into inactive matrix would remarkably improve the catalytic reactivity. Our first-principles calculations show that the reaction barrier of methane dehydrogenation is remarkably reduced from 1.76 eV on flat Cu (100) surface to 1.00 eV on a Ni atom adsorbed Cu (100) surface. Moreover, the adsorbed Ni atom is found to serve as the active reaction center, which might provide a possibility of manipulating the graphene nucleation position for controllable chemical vapor deposition growth. Additionally, different dehydrogenation behaviors are detected and well understood in terms of electronic structures involved in the reactions. This study shows the potential of synthesizing high-quality graphene at relatively low temperatures with the assistance of Ni adsorption on Cu foils, and it can be extended to other metal and substrates.

The presence of the intrinsic band gap of 3.06 eV makes atomically thin carbon nitride sheets (CNs) a promising spin-based semiconductor material. However, the absence of localized spins makes the pristine CNs intrinsically nonmagnetic. Here we report the realization of strong room-temperature (RT) ferromagnetism with a high Curie temperature of ca. 524.2 K in atomically thin 2D CNs by annealing pristine CNs at 700 °C. In particular, the RT saturated magnetization reaches as high as 0.71 emu/g, which is the highest value reported so far in carbon-based materials. The structural characterization combined with density functional theory calculations reveals that (i) the seven C–C bonds per unit cell were formed after annealing and (ii) the C–C bonds can introduce high-density localized spins and realize the long-range ferromagnetic couplings among these spins.