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

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 Ni 2 MnGa microparticles and report their EMW absorbing properties for the first time. The as-milled Ni 2 MnGa/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 RL min 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. The continuous dual-absorption peaks are realized in ball-milled Ni 2 MnGa micro-sized particles for the first time, which substantially broaden the effective absorption bandwidth. The optimal EMW absorbing performance with the minimum reflection loss value up to −65.2 dB is achieved at a frequency of ∼14.4 GHz with a thickness of 2.90 mm in ball-milled microparticles. Image 1 • The continuous dual-absorption peaks are realized in ball-milled Ni 2 MnGa particles. • The permeability-to-permittivity transformation in Ni 2 MnGa microparticles are reported. • The dual-absorption peaks substantially broaden the effective absorption bandwidth. • The optimal RL min value up to −65.2 dB is achieved at the frequence of ∼14.4 GHz. [ABSTRACT FROM AUTHOR]