Influence of Low-temperature Heat-treatment on the Structure and Properties of Fe@Ag Composite Particles

In order to reduce the resistivity of Fe@Ag composite particles,the influence of heat-treatment tempera-ture(T) on the structure,resistivity and magnetic properties of the Fe@Ag composite particles,and the shielding ef-fectiveness(SE) of the electromagnetic shielding rubber containing the Fe@Ag composite particles were studied.The results show that with heat-treatment temperature increasing from 120℃ to 170℃,the Fe@Ag composite particles heat-treacted at 140℃ have the most compact silver-shells and the lowest volume resistivity,while the saturation mag-netization almost keeps unchanged.The electromagnetic shielding rubber containing the Fe@Ag composite particles heat-treated at 140℃ has SE of -28 dB to -53 dB,which is -10 dB to -15 dB higher than that of the particles without heat-treatment.The morphology evolution and related property changes with T are reasonably explained by the interface wetting theory and crystal growth theory.Low-temperature heat-treatment provides a simple and convenient approach to obtain electromagnetic shielding fillers with high performance.