Recycle of rare earth sintered magnet powder scraps as electromagnetic wave absorbers in gigahertz range

The electromagnetic (EM) wave absorbers were prepared from the magnetite powders obtained as a byproduct in the recycle process for the sludge powder scraps of NdFeB-type sintered magnets. The resulting EM wave absorbers showed the minimum RL value of −32 dB at 16.5 GHz with 1.2 mm thickness. Reduction of the magnetite powders leads to improve the EM wave absorption properties (RL