Effect of annealing temperature on the magnetic and microwave absorption of FeNi alloy

FeNi alloys were synthesized by hydrothermal reduction method. The effects of different annealing temperatures on magnetic properties and microwave absorption properties were investigated. As the annealing temperature increases from 150 degrees C to 700 degrees C, the saturation magnetization of FeNi alloys increases from 83.61 to 103.24 A center dot m(2)center dot kg(-1), and the coercivity decreases from 12.18 to 0.68 kA center dot m(-1). FeNi alloy changes from semi-hard magnetic behavior to typical soft magnetic behavior. The optimum reflection loss (RL) of the FeNi alloy (700 degrees C) is-28.36 dB at 3.84 GHz. Especially, the effective absorption bandwidth (RL < -10 dB) of FeNi alloy (700 degrees C) is up to 3.26 GHz. These results suggest that the FeNi alloys could be a desirable S-band operational microwave absorber.

Automated summary

FeNi alloys were synthesized by hydrothermal reduction method, and the effects of different annealing temperatures on their magnetic and microwave absorption properties were investigated. With increasing annealing temperature from 150 degrees C to 700 degrees C, the saturation magnetization of FeNi alloys increased from 83.61 to 103.24 A·m2·kg-1, while the coercivity decreased from 12.18 to 0.68 kA·m-1. The FeNi alloy changed from semi-hard magnetic behavior to typical soft magnetic behavior. The FeNi alloy (700 degrees C) exhibited an optimum reflection loss (RL) of -28.36 dB at 3.84 GHz, and an effective absorption bandwidth (RL < -10 dB) up to 3.26 GHz.