Influence of the element ratios on the static magnetic properties and electromagnetic absorption performance of certain spherical CoNi crystal particles

CoNi crystal absorption particles were prepared with chemical liquid phase reduction, and the microstructure, static magnetic properties, and absorption characteristics were investigated. Higher nickel content results in spherical morphology, while an increase in Co content leads to larger particle sizes and nonlinear surface morphology, with crystallinity decreasing with reduced Ni content. The specific saturation magnetization intensity of CoNi alloy particles increases with rising Co content, while the residual magnetization and coercivity exhibit fluctuating behaviors, which are typical nonlinear responses induced by the coupling of composition, particle size, and crystallinity. In the low-frequency range, the real part of the complex dielectric constant of CoNi alloy particles remains relatively stable, with the imaginary part showing a gradual increase at low frequencies and fluctuations at high frequencies. The real part of the complex magnetic permeability exhibits a decreasing trend in the low-frequency range, while the imaginary part shows a gradual increase, reflecting the nonlinear frequency dispersion characteristics. The reflection loss (RL) of the four samples decreases with decreasing Ni content, with CN-1 exhibiting a maximum RL of -6.94dB at 14GHz, which is attributed to the nonlinear complementary effect of dielectric loss and magnetic loss.