Synthesis, magnetic and electromagnetic wave absorption properties of planar anisotrop Y2Co17@SiO2 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 Y2Co17 alloy via the co-precipitation reduction-diffusion technique,then coated the Y2Co17 magnetic powders with SiO2 to create Y2Co17@SiO2 core-shell structures.The formation of Y2Co17@SiO2/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 Y2Co17@SiO2/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 Y2Co17@SiO2/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.