Enhanced electromagnetic wave absorption properties of Ni2MnGa microparticles due to continuous dual-absorption peaks

Abstract Achieving continuous dual-absorption peaks in ferromagnetic materials with micron-sized particles is quite challenging in designing the potential electromagnetic wave (EMW) absorbing materials. Here, we realize this effect in ball-milled Ni2MnGa microparticles and report their EMW absorbing properties for the first time. The as-milled Ni2MnGa/paraffin-bonded hybrids exhibit highly efficient EMW absorbing performance owing to the continuous dual-absorption peaks induced by enhanced dielectric loss and weakened magnetic loss associated with the permeability-to-permittivity energy transformation at the frequency of 2.0–18.0 GHz. The optimal EMW absorbing properties with the RLmin value up to −65.2 dB can be obtained at a frequency of ∼14.4 GHz with a thickness of 2.90 mm. The effective absorption bandwidth with RL values less than −10 dB can reach 12.7 GHz through tuning the absorber thickness. It is demonstrated that Heusler-type NiMn-based alloys could be an attractive mono-component ferromagnetic absorber with highly efficient dual-absorption peaks.