Pushing the boundaries of magnet design (Vol. 48 No. 1)

New method to make permanent magnets more stable over time

For physicists, loss of magnetisation in permanent magnets can be a real concern. In response, the Japanese company Sumitomo created the strongest available magnet—one offering ten times more magnetic energy than previous versions—in 1983. These magnets are a combination of materials including rare-earth metal and so-called transition metals, and are accordingly referred to as RE-TM-B magnets. The authors have now been pushing the boundaries of magnet design, as published in a recent study. They have developed methods to counter the spontaneous loss of magnetisation, based on their understanding of the underlying physical phenomenon. They have now developed a simple additive-based method for ensuring the stability of permanent magnets over time, with no loss to their main magnetic characteristics.

R. B. Morgunov, E. I. Kunitsyna, V. V. Kucheryaev, V. P. Piskorskii, O. G. Ospennikova and E. N. Kablov, Giant effect of Sm atoms on time stability of (NdDy)(FeCo)B magnet, Eur. Phys. J. Plus, 131, 344 (2016)
[Abstract]