The magnetic and microwave absorbing properties of the as spun Nd-Fe-Co-B nanocomposites

Highlights: •Magnetic and electromagnetic properties of quenched Co-doped NdFeB alloys were studied. •The quenched Co-doped NdFeB alloys exhibit a single α-Fe phases soft magnetic properties and have excellent absorbing properties at 2–18 GHz. - Abstract: In this paper, microstructure, magnetic and microwave absorbing properties of Nd_xFe_85−xCo₄B₁₁ nanocomposites (x = 3, 5, 7, 9) flaky-shaped particles prepared by melt spun were investigated. The analyses of XRD spectra suggest that all samples only have the single $\alpha$-Fe phase. With the increase of the Nd content, the complex permittivity-frequency and permeability-frequency were increased at first, and then decreased with higher Nd content. The resin composites of 70 wt% of these nanocomposite powders showed excellent electromagnetic wave absorption properties in GHz range. A minimum reflection loss of −23.1 dB is obtained at 9.8 GHz for composite Nd₉Fe₇₆Co₄B₁₁.