Synthesis, magnetic and electromagnetic wave absorption properties of planar anisotrop Y₂Co₁₇@SiO₂ rare earth soft magnetic composites

【摘要】 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 Y₂Co₁₇alloy via the co-precipitation reduction-diffusion technique, then coated the Y₂Co₁₇magnetic powders with SiO₂to 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 d B） and excellent microwave absorption properties with an average RL of Y₂Co₁₇@SiO₂/PU being below-10 d B 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.更多还原

【Abstract】 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 Y₂Co₁₇alloy via the co-precipitation reduction-diffusion technique, then coated the Y₂Co₁₇magnetic powders with SiO₂to 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 d B） and excellent microwave absorption properties with an average RL of Y₂Co₁₇@SiO₂/PU being below-10 d B 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.更多还原