New and old materials for permanent magnets based on earth-abundant elements

Sammanfattning: Electrical motors, which find use in e.g. electrical vehicles, require per-manent magnets to function. Comparing ferrite magnets and Nd-based magnets reveals a large difference in their price and performance. During the last decade, gap-magnets, with performance in between ferrites and Nd-based magnets have attracted considerable research interest world-wide due to the “rare-earth crisis”. During this crisis, the price of certain rare-earth elements experienced volatile changes. This thesis deals with materials that could be relevant as gap-magnets. The thesis starts with introducing key properties and constraints relevant for gap-magnets. In the thesis, four different systems were investigated. The four systems show that permanent magnets need to be understood and optimized on three distinct levels, the crystal level, the structural level, and the micro-structural level. They show how old and new materials can potentially be utilized as permanent magnets. Lastly, the thesis ends with an outlook that presents new ideas for finding new permanent magnets. The ideas presented in the outlook are ideas that were not treated in this thesis, and thus may represent new ways for further work in developing materials for gap-magnets.