Electromagnetic performance analysis of NiFe₂O₄ hollow particles

In the field of photoelectric passive interference, spinel ferrite has a significant attenuation ability of electromagnetic waves in the 2-18 GHz cm band. However, in practical applications, it is difficult for ferrite to form large-scale electromagnetic wave attenuation aerosols in the air due to its heavy ratio. In this paper, the magnetic NiFe₂O₄ hollow particles were obtained by preparing them using the hydrothermal method assisted by glucose, which showed excellent electromagnetic loss performance. The changes in particle retention (volume growth value) and electromagnetic wave absorption performance with the hollow rate were analyzed. The electromagnetic wave absorption cross section and relative volume growth value of hollow particles with different particle sizes and hollow rates were obtained by theoretical calculation. The electromagnetic parameters of magnetic NiFe₂O₄ hollow particles with different ratios of glucose and metal ions were measured by Vector Network Analyzer. The effects of ratios of glucose and metal ions on the electromagnetic loss of magnetic NiFe₂O₄ hollow particles were investigated. The ratio of glucose to metal ions has a threshold of 20:11.25. Increasing or decreasing the metal ions will reduce its electromagnetic loss performance. The reflection loss can reach the minimum value of -24 dB at 5.3 GHz.