FeCo alloy nanowires exhibit high saturation magnetization and tunable anisotropy, making them attractive for self-biased microwave devices. However, their magnetic performance is limited by magnetostatic interactions and multi-domain states that degrade coercivity and remanence squareness. This work demonstrates that nanowire diameter directly governs this magnetic complexity. Using experiment and micromagnetic simulation on electrodeposited Fe₆₆Co₃₃ nanowire arrays, we reveal a sharp transition from multi-domain to single-domain configurations below 30 nm. This transition is visualized by scanning nitrogen-vacancy magnetometry and Lorentz transmission electron microscopy. First-order reversal curve analysis quantifies a significant reduction in inter-wire magnetostatic coupling with decreasing diameter, indicating improved magnetic uniformity. Dynamic simulations show that larger diameters introduce multi-domain resonance modes and enhance inter-wire coupling, leading to complex collective behavior. Ferromagnetic resonance spectroscopy provides key material parameters, including gyromagnetic ratio, Gilbert damping constant, and saturation magnetization derived from an effective field model. These results establish that precise diameter control below 30 nm optimizes individual nanowire properties while suppressing array-level coupling, resulting in enhanced coercivity and a stable single-domain state. As a demonstration, a Y‑junction circulator based on these nanowire arrays shows promising microwave performance. This work offers a materials-oriented roadmap for engineering high-performance self-biased magnetic devices.

Polarization camera based on CMOS sensor and nano wire-grid technology have found widespread applications in medical diagnostics, remote sensing and industrial inspection. However, the limited filtering properties of wire-grid polarizers and the small field-of-view provided by conventional microlens restrict the energy efficiency of these systems while also increasing their cost, size and weight. In this study, we propose an innovative approach that integrates focusing and splitting of polarization states into a single-layer all-dielectric metasurface. This metasurface enables full-Stokes polarization imaging for a wide field-of-view conical light. The design of the metasurface utilizes a phase compensation method to effectively focus orthogonal polarized conical light onto the central pixel of the CMOS sensor. Theoretical analysis demonstrates that this metasurface can accurately detect full-Stokes parameters within ±20° incident cone angles with an average efficiency reaching 83.0%. The angle can be extended to ±90° with an average efficiency exceeding 80%. We fabricated a three super-pixel metasurface prototype, and experimental measurements reveal its ability to efficiently focus and split three pairs of orthogonal polarization states under ±11° conical angle incidence with an average focusing efficiency of 68.1%. This study presents a promising solution for achieving wide field-of-view and high-efficiency polarization detection in integrated CMOS systems.

Environmentally-friendly magnetic metallic absorbers with high-performing antioxidant property, thermal stability, and anti-corrosion capability have attracted great attention in real-world applications. A surface modification technology of magnetic metallic absorbers with dense and inert materials has been an effective strategy to solve the aforesaid problem. Herein, fluorine-free core–shell carbonyl iron-organic silicon absorbers (CI@SiO₂/1,1,1,3,3,3-hexamethyl disilazane (HMDS)) were fabricated via a facile one-pot synthesis using tetraethyl orthosilicate (TEOS) and HMDS as the precursor of protective layer (SiO₂/HMDS), and CI@SiO₂/HMDS hybrid reveals its long-term corrosion resistance and excellent microwave absorption performance with a minimum reflection loss value of −44.3 dB and an effective absorption bandwidth of 5.3 GHz at a thin thickness of 2.0 mm after immersion in 5.0 wt.% NaCl acidic solutions for 2,160 h. Meanwhile, CI@SiO₂/HMDS hybrid can still achieve the maximum radar cross-sectional (RCS) reduction values about 16.5 dB·m² at the detection θ of 0°. The exceptional microwave absorption performance and structural stability are largely due to the extraordinary wave-transparent property and shielding ability against corrosive medium of SiO₂/HMDS hydrophobic protective layer with a contact angle of 132.5°. The research paves the way for the large-scale and batch production of high-performance magnetic metallic absorbers and increases their survivability and reliability in the harsh environments.