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Programmable magnetic field-free manipulation of perpendicular magnetization switching is essential for the development of ultralow-power spintronic devices. However, the magnetization in a centrosymmetric single-layer ferromagnetic film cannot be switched directly by passing an electrical current in itself. Here, we demonstrate a repeatable bulk spin-orbit torque (SOT) switching of the perpendicularly magnetized CoPt alloy single-layer films by introducing a composition gradient in the thickness direction to break the inversion symmetry. Experimental results reveal that the bulk SOT-induced effective field on the domain walls leads to the domain walls motion and magnetization switching. Moreover, magnetic field-free perpendicular magnetization switching caused by SOT and its switching polarity (clockwise or counterclockwise) can be reversibly controlled in the IrMn/Co/Ru/CoPt heterojunctions based on the exchange bias and interlayer exchange coupling. This unique composition gradient approach accompanied with electrically controllable SOT magnetization switching provides a promising strategy to access energy-efficient control of memory and logic devices. A major challenge of spintronics is achieving magnetic field free electrical control of magnetisation. Here, Xie et al. achieve perpendicular magnetisation switching in a CoPt alloy, breaking inversion symmetry by varying the composition of the alloy in the growth direction.

Large-area vertical rutile TiO 2 nanorod arrays (TNAs) were grown on F/SnO 2 conductive glass using a hydrothermal method at low temperature. A self-powered ultraviolet (UV) photodetector based on TiO 2 nanorod/water solid–liquid heterojunction is designed and fabricated. These nanorods offer an enlarged TiO 2 /water contact area and a direct pathway for electron transport simultaneously. By connecting this UV photodetector to an ammeter, the intensity of UV light can be quantified using the output short-circuit photocurrent without a power source. A photosensitivity of 0.025 A/W and a quick response time were observed. At the same time, a high photosensitivity in a wide range of wavelength was also demonstrated. This TNA/water UV detector can be a particularly suitable candidate for practical applications for its high photosensitivity, fast response, excellent spectral selectivity, uncomplicated low-cost fabrication process, and environment-friendly feature.

Photoelectrochemical cell-typed self-powered UV detectors have attracted intensive research interest due to their low cost, simple fabrication process, and fast response. In this paper, SnO 2 -TiO 2 nanomace arrays composed of SnO 2 nanotube trunk and TiO 2 nanobranches were prepared using soft chemical methods, and an environment-friendly self-powered UV photodetector using this nanostructure as the photoanode was assembled. Due to the synergistic effect of greatly accelerated electron-hole separation, enhanced surface area, and reduced charge recombination provided by SnO 2 -TiO 2 nanomace array, the nanostructured detector displays an excellent performance over that based on bare SnO 2 arrays. The impact of the growing time of TiO 2 branches on the performance of UV photodetector was systematically studied. The device based on optimized SnO 2 -TiO 2 nanomace arrays exhibits a high responsivity of 0.145 A/W at 365 nm, a fast rising time of 0.037 s, and a decay time of 0.015 s, as well as excellent spectral selectivity. This self-powered photodetector is a promising candidate for high-sensitivity, high-speed UV-detecting application.

This study investigates the collapse behavior and energy absorption capabilities of epoxy/carbon composite absorbers using finite element analysis (FEA) in ABAQUS software. The analysis focuses on different geometrical cross-sections (circular, square, and octagonal) and various fiber orientations (0°, 30°, 45°, 60°, and 90°). The simulation results are validated against experimental data from previous studies to ensure accuracy. The findings reveal that nonzero fiber orientations induce twisting, altering stress distribution and reducing geometric stability. The highest energy absorption capacity was registered for the circular sections among the investigated geometries; the maximum collapse force for octagonal sections with a fiber orientation of 60° was increased by 35% and 49% with respect to the cylindrical and square sections, respectively. Also, in the case of an octagonal section, the maximum average absorbed energy occurs at a fiber orientation of 51.3°. The octagonal cross-section, especially for fiber orientation of 46.4°, demonstrates a better maximum peak load than the rest of the geometries. In this study, the critical effect of fiber orientation on the collapse behavior and energy absorption was underlined; for instance, a 0° fiber orientation behaves like a soft material, while 90° behaves like a brittle one, providing different modes of collapse. The results indicate how composite materials could be optimized for energy absorption applications.

Coherent light sources in the visible range are playing important roles in our daily life and modern technology, since about 50% of the capability of the our human brains is devoted to processing visual information. Visible lasers can be achieved by nonlinear optical process of infrared lasers and direct lasing of gain materials and the latter has advantages in the aspects of compactness, efficiency, simplicity, etc. However, due to lack of visible optical modulators, the directly generated visible lasers with only a gain material are constrained in continuous-wave operation. Here, we demonstrated the fabrication of a visible optical modulator and pulsed visible lasers based on atomic-layer molybdenum sulfide (MoS 2 ), a ultrathin two-dimensional material with about 9–10 layers. By employing the nonlinear absorption of the modulator, the pulsed orange, red and deep red lasers were directly generated. Besides, the present atomic-layer MoS 2 optical modulator has broadband modulating properties and advantages in the simple preparation process. The present results experimentally verify the theoretical prediction for the low-dimensional optoelectronic modulating devices in the visible wavelength region and may open an attractive avenue for removing a stumbling block for the further development of pulsed visible lasers.

Long-range tunable strongly coupled photon-magnon systems are crucial for large-scale hybrid networks enabling coherent information processing. Here, we experimentally fabricate a photon-magnon system with a saturable gain, achieving long-range strong coupling in the linear regime for the first time, aside from the nonlinear regime. By modulating the propagation phase of traveling waves mediating photons and magnons, we achieve flexible switching between coherent coupling and dissipative coupling. Theoretically, we construct a Hamiltonian model comprising a van der Pol oscillator and a harmonic oscillator, from which we derive the dynamical equations of the cavity magnonic system and numerically simulate the time evolution of photon and magnon modes amplitudes under the long-range strong coupling. The results reveal energy exchange in the linear regime and mode synchronization in the nonlinear regime. Our work integrates experimental results and theoretical models, establishing a foundation for cross-platform information exchange and controllable coupling in hybrid systems.

Lithium-ion (Li-ion) batteries based on spinel transition-metal oxide electrodes have exhibited excellent electrochemical performance. The reversible intercalation/deintercalation of Li-ions in spinel materials enables not only energy storage but also nondestructive control of the electrodes’ physical properties. This feature will benefit the fabrication of novel Li-ion controlled electronic devices. In this work, reversible control of ferromagnetism was realized by the guided motion of Li-ions in MnFe 2 O 4 and γ-Fe 2 O 3 utilizing miniature lithium-battery devices. The in-situ characterization of magnetization during the Li-ion intercalation/deintercalation process was conducted, and a reversible variation of saturation magnetization over 10% was observed in both these materials. The experimental conditions and material parameters for the control of the ferromagnetism are investigated, and the mechanism related to the magnetic ions’ migration and the exchange coupling evolution during this process was proposed. The different valence states of tetrahedral metal ions were suggested to be responsible for the different performance of these two spinel materials.

Multiferroic BiFeO3 (BFO) thin films have attracted significant attention for spintronic applications due to their strong magnetoelectric coupling at room temperature. However, the application of BFO remains at the laboratory stage, and low‐temperature, large‐scale preparation of BFO thin film still constitutes a challenge. In this study, the growth conditions of single‐crystalline BFO, La‐doped Bi1‐xLaxFeO3 (BLFO), and ferromagnetic/BLFO heterostructures are optimized based on magnetron sputtering techniques. The following achievements are realized: 1) Epitaxial growth of BFO thin films at 440 °C, which is below the CMOS‐compatible temperature; 2) Optimization of La doping at 550 °C to enhance the epitaxial quality (ω scan FWHM = 0.12), reduce leakage current (Jc ≈ 10−2 mA cm−2), and lower the ferroelectric switching voltage (1.83 V) of BLFO; 3) Achievement of a large exchange bias (Hex = 85.1 Oe) with Hex/coercive field(Hc)>1 in CoFeB/BLFO heterostructures. These achievements advance the broader application of BFO and lay the foundation for voltage‐controlled field‐free switching in ultra‐low‐power spintronic devices. This study explores the epitaxial growth of high‐quality La‐doped BiFeO3 (BLFO) thin films at 550 °C using magnetron sputtering. The films exhibit good ferroelectric properties and low leakage current. A BLFO/CoFeB heterostructure is constructed, achieving an exchange bias field exceeding the coercive field at room temperature.

Manipulating the magnetic order transition of 2D magnetic materials is an important way for the application of spintronic devices, and carrier concentration modulation is a commonly used effective regulation method. Here the magnetic ground state of FePS3 is tuned from antiferromagnetic (AFM) to ferrimagnetic (FIM) and back to AFM by electron doping, which is achieved via the intercalation of various organic cations. The doped FePS3 with FIM order exhibits a Curie temperature Tc of ≈110 K, a strong out‐of‐plane magnetic anisotropy, and particularly an unusual hysteresis loop, where with increasing temperature, the area of magnetic hysteresis loop increases below 50 K, then decreases above 50 K and eventually disappears. Theoretical calculations indicate that at a doping concentration of 0.3–0.9 electrons per cell, spin splitting of energy bands occurs, leading to the FIM order; whereas at a doping concentration of ≥ 1.0 electrons per cell, the AFM order recovers. Such AFM‐FIM‐AFM transition is ascribed to the competition between the Stoner exchange‐dominated FM order and super‐exchange‐dominated AFM order. These results demonstrate an effective approach to engineering magnetism in 2D magnetic materials by purely electrical means for future device applications. The magnetic order transition of FePS3 from antiferromagnetic (AFM) to ferrimagnetic (FIM) and back to AFM is achieved via electron doping induced by various organic cations intercalation. The carrier doping‐dependent magnetic transition offers an effective approach to engineering magnetism in 2D magnetic materials by purely electrical means for future device applications.

Nanostructures composited of vertical rutile TiO 2 nanorod arrays and Sb 2 S 3 nanoparticles were prepared on an F:SnO 2 conductive glass by hydrothermal method and successive ionic layer adsorption and reaction method at low temperature. Sb 2 S 3 -sensitized TiO 2 nanorod solar cells were assembled using the Sb 2 S 3 -TiO 2 nanostructure as the photoanode and a polysulfide solution as an electrolyte. Annealing effects on the optical and photovoltaic properties of Sb 2 S 3 -TiO 2 nanostructure were studied systematically. As the annealing temperatures increased, a regular red shift of the bandgap of Sb 2 S 3 nanoparticles was observed, where the bandgap decreased from 2.25 to 1.73 eV. At the same time, the photovoltaic conversion efficiency for the nanostructured solar cells increased from 0.46% up to 1.47% as a consequence of the annealing effect. This improvement can be explained by considering the changes in the morphology, the crystalline quality, and the optical properties caused by the annealing treatment.