(a) Magnetic hysteresis loops of the HD powders with (1) 0 wt.%, (2) 5 wt.%, and (3) 10 wt.% NdH_x nanoparticles heated at 800 °C for 1 h. (b) Magnetic hysteresis loops of the HD powders with (1) 0 wt.%, (2) 5 wt.%, and (3) 10 wt.% NdH_x nanoparticles heated at 700 °C for 5 h. (c) Demagnetization curve of the recycled Nd–Fe–B bonded magnet made from the powders with 10 wt.% NdH_x nanoparticles heated at 700 °C for 5 h.^[34]