Synthesis, magnetic and electromagnetic wave absorption properties of planar anisotrop Y2Co ₁₇@SiO ₂ rare earth soft magnetic composites

Intermetallic complexes of rare-earth and 3d transition metals with core-shell structures are commonly employed as microwave absorbing materials due to their high saturation magnetizations and natural resonance in GHz. Hence, we synthesized Y ₂Co ₁₇ alloy via the co-precipitation reduction-diffusion technique, then coated the Y ₂Co ₁₇ magnetic powders with SiO ₂ to create Y ₂Co ₁₇@SiO ₂ core-shell structures. The formation of Y ₂Co ₁₇@SiO ₂/polyurethane (PU) at various volume fractions and their magnetic, electromagnetic properties were investigated using x-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, and vector network analyzer. The microwave absorption characteristics of Y ₂Co ₁₇@SiO ₂/PU were also investigated at various volume fractions. We not only investigate the zero-reflection conditions of the samples with different volume fractions, but also show that every absorber has a strong reflection loss value (RL ≤ −65.00 dB) and excellent microwave absorption properties with an average RL of Y ₂Co ₁₇@SiO ₂/PU being below −10 dB at 8 GHz–18 GHz under different thicknesses, showing that the enhancement of microwave absorption performance arises from the balance between permeability and permittivity of absorber.