Transactions of Nonferrous Metals Society of China (中国有色金属学报)•2026•DOI: 10.1016/S1003-6326(26)67064-1
The influence of thickness and annealing treatment on the microstructure and soft magnetic properties of Fe−Si−B−Cu−Nb alloy (Finemet) thin films prepared by magnetron sputtering was systematically investigated. As-deposited films are amorphous; coercivity decreases and saturation magnetization increases with thickness, stabilizing at 400 nm. Annealing at 773 K and 873 K precipitates nanocrystalline α-Fe within the amorphous matrix. Exchange coupling between nanocrystals and the amorphous matrix enhances soft magnetic properties. Rapid thermal processing (RTP) controls the heating rate to minimize grain size and optimize nanocrystal distribution, achieving low coercivity and high saturation magnetization without additional transition metals. The film annealed at 873 K for 30 min with a heating rate of 25 K/s exhibits a coercivity of 0.8 A/m and saturation magnetization of 1.45 T. Compared to the 773 K annealed film, the 873 K annealed film shows significantly lower coercivity due to smaller precipitated nanocrystals. RTP with controlled thermal gradient enables even smaller nanocrystals, further enhancing magnetic properties. These results demonstrate that RTP-treated Finemet films are promising for high-frequency, miniaturized, and integrated electronic devices.
Journal of Semiconductors (半导体学报 - 中国科学院半导体研究所)•2026•DOI: 10.1088/1674-4926/25120042
GaN-based vertical-cavity surface-emitting lasers (VCSELs) are constrained by the absence of p-type conductive epitaxial distributed Bragg reflectors (DBRs), forcing reliance on dielectric DBRs that impose high thermal resistance or complex substrate removal. This work demonstrates a room-temperature electrically injected GaN VCSEL incorporating a conductive nanoporous (NP) GaN DBR fabricated by electrochemical etching of alternating n-GaN layers with varying Si doping. The NP-GaN DBR exhibits low electrical resistance, enabling vertical current injection. Under pulsed operation, the device with a 10-μm aperture lases at 427.7 nm with a full width at half maximum (FWHM) of 0.8 nm. The threshold current is 26 mA, corresponding to a threshold current density of approximately 33 kA/cm². Polarization degree increases from 35% below threshold to 86% above threshold, confirming lasing. The turn-on voltage remains high, primarily due to p-side resistance. These results validate the potential of conductive NP-GaN DBRs for high-density two-dimensional VCSEL arrays, though further reduction of p-side resistance is required for continuous-wave operation.
Transactions of Nonferrous Metals Society of China (中国有色金属学报)•2025•DOI: 10.1016/S1003-6326(25)66983-4
The dependence of interface structure and mechanical properties on the modulation layer thickness of VN/TiN−Ni nano-multilayered films deposited on Si substrates using a reactive magnetron sputtering technique was systematically investigated. The films were characterized using X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, transmission electron microscopy, and nanoindentation. The results show that the TiN−Ni layer grows epitaxially on the VN layer, forming a coherent interface between the two sublayers. When the deposition time ratio of the two sublayers (TTiN−Ni꞉TVN) is 10꞉12, the films exhibit remarkable mechanical properties, with hardness, elastic modulus, and fracture toughness values of 25.9 GPa, 317 GPa, and 1.88 MPa·m1/2, respectively. Meanwhile, fracture toughness is improved by approximately 50% compared to the VN monolithic film. This enhancement is attributed to the coherent interface between the sublayers and the phase separation in the TiN−Ni layer.
Journal of Semiconductors (半导体学报 - 中国科学院半导体研究所)•2025•DOI: 10.1088/1674-4926/25020024
Low power consumption, high responsivity, and self-powering are key objectives for photoelectrochemical ultraviolet detectors. In this research, In-doped α-Ga2O3 nanowire arrays were fabricated on fluorine-doped tin oxide (FTO) substrates through a hydrothermal approach, with subsequent thermal annealing. These arrays were then used as photoanodes to construct a ultraviolet (UV) photodetector. In doping reduced the bandgap of α-Ga2O3, enhancing its absorption of UV light. Consequently, the In-doped α-Ga2O3 nanowire arrays exhibited excellent light detection performance. When irradiated by 255 nm deep ultraviolet light, they obtained a responsivity of 38.85 mA/W. Moreover, the detector's response and recovery times are 13 and 8 ms, respectively. The In-doped α-Ga2O3 nanowire arrays exhibit a responsivity that is about three-fold higher than the undoped one. Due to its superior responsivity, the In-doped device was used to develop a photoelectric imaging system. This study demonstrates that doping α-Ga2O3 nanowire with indium is a potent approach for optimizing their photoelectrochemical performance, which also has significant potential for optoelectronic applications.
Int. Journal of Mining Science and Technology (采矿与安全工程)•2025•DOI: 10.1016/j.ijmst.2025.06.001
Obtaining high-quality 10000-meter-deep seafloor sediment samples is the prerequisite and foundation for conducting deep-sea geological and environmental scientific research. The bottom structure of the deep seafloor is complex, and the physical and mechanical properties and disturbance resistance of sediments of different lithologies vary greatly, so the sediment sampler inevitably disturbs the sediments during the sampling process and affects the quality of the sediment samples. A new type of deep-sea sediment pressure retaining sampler is introduced, the force state and elastic–plastic state of the sampler destroying sediments are analyzed, the radial disturbance model of sediment coring based on the spherical cavity expansion theory is established, and the radius of sediments undergoing plastic deformation around the spherical holes is used as an index for evaluating the radial disturbance of sediments. The distribution of stress and strain fields in the sediments during the expansion of the spherical cavity and the influencing factors of the radius of the radially disturbed region (plastic region) are analyzed using an arithmetic example, and the influence law is analyzed. A sediment disturbance experimental platform was built indoors to simulate the sediment coring process. The radial stress field and pore water pressure of the sediment during the coring process were monitored by sensors arranged inside the sediment, and the results of indoor tests verified the correctness of the perturbation theory model. The sampler was carried aboard the deep-sea manned submersible FENDOUZHE and conducted on-site tests at depths of 9298.4 and 9142.8 m in the Kuril-Kamchatka Trench. Pressure-preserved sediment samples were retrieved, with preservation rates of 94.21% and 92.02%, respectively, which are much higher than the current technical indicator of 80% of pressure-holding ratio for deep-sea sediments. The retrieved sediments have obvious stratification characteristics and little disturbance.