Amorphous FexB100−x nanostructures with tunable boron contents were fabricated.
Amorphous FexB100−x shows enhanced microwave absorption compared to crystalline one.
The maximum RL of amorphous FexB100−x was −39.4 dB at 4.2 GHz with 2.0 mm.
Amorphous FexB100−x can be used as high-efficient microwave absorber at S or C band.