Tailoring exchange coupling at MgO/(FeCoNi)86Al7Ti7 interfaces for concurrent soft magnetic enhancement and GHz-Range electromagnetic dissipation

In this paper, (FeCoNi) 86 Al 7 Ti 7 high entropy alloys powder is mixed with different concentrations of MgO to prepare high entropy alloys composites. Soft magnetic and wave-absorbing properties of composites characterized and analyzed. The results show that MgO has a role in reducing the total loss of magnetic powder cores. The best soft magnetic performance is obtained when the addition amount is 0.25 wt%, with a total loss of 1455 mW/cm 3 ( f  = 1000 kHz, B m  = 5mT), and the saturation magnetization strength shows a decreasing trend with the increase of MgO content. Significantly improved wave-absorbing performance in the 2–18 GHz band with the addition of MgO. When the added MgO content is 0.25 wt%, the samples have the best wave-absorbing properties. The thickness is 4.5 mm, the minimum reflection loss is −41.2 dB at 7.3 GHz, the effective absorption bandwidth is 3 GHz (5.6–8.6 GHz), and it has excellent wave-absorbing performance.