1. Context

In the field of functional materials, high-Curie temperature magnetic materials are the basis for vast technological developments, both in electrical engineering and in high-density magnetic recording. In these fields, with the third generation of materials for permanent magnets represented by alloys based on rare earth and transition metals making constant progress, hopes are still high.

The simultaneous discovery in the 1980s in Japan and the USA of the anisotropic alloy Nd ₂ Fe ₁₄ B made it possible to replace the SmCo ₅ magnet, which had become too expensive, despite its intrinsic characteristics. In this new direction, the challenge offered to the scientific community was to develop methods for stabilizing cheap iron in new...