The incumbent technology – neodymium-iron-boron, sometimes with dysprosium – works well, but Nd and Dy are considered minerals or strategic importance by nations which mine them, and are mostly found in China where exports are restricted.
Working together, the Japanese National Institute for Materials Science (NIMS) and Tohoku Gakuin University have looked at samarium – already used in samarium-cobalt magnets, which were essentially the more-expensive predecessor to Ne-Fe-B magnets.
