Enhanced energy product in Y-Co-Fe magnets intermediate between Nd-Fe-B and ferrite

The hysteresis of ball-milled Fe-doped YCo5 powder has been optimized by controlling the temperature and time for rapid annealing under vacuum and argon. The crystallite size is only 25 nm; yet, it has been possible to field align Y(Co, Fe) powder with a 5-20 mu m grain size in a 5 T field to obtain a remanence ratio of 0.65, due to texture in the ball-milled powder. The nominal energy product of the powder is 140 kJ/m(3). A pressed magnet with 78% of theoretical density has an energy product of 65 kJ/m(3). This magnet could fill the gap between oriented ferrite (34 kJ/m(3)) and oriented Nd-Fe-B (350 kJ/m(3)). (C) 2015 AIP Publishing LLC.