Presentation Information
[O15-2]The Possibility of New Complex Magnet Materials
*Jeff Snyder1 (1. ARPA-E and Northwestern University (United States of America))
Keywords:
materials discovery
Magnets are needed for numerous applications including essential consumer electronic components, electric motors that power industry and the future of transportation as well as generating and transforming most electric power. Strong magnets reduce the size and weight of electric motors and generators. The maximum magnetic field produced by a magnet is determined by the Saturation Magnetization Bs, related to the density of unpaired spins. Simple iron-based alloys have the highest Bs with about 2 unpaired spins per atom. Given that there are many atoms with 5 or more unpaired spins higher Bs should be possible. Many applications require permanent magnets with high coercivity Hc as well as high Bs where the best metric is the maximum B x H product. Since the almost accidental discovery of Nd2Fe14B-based materials in 1980s, no new magnet material has exceeded its performance. Nd2Fe14B has a crystal structure and chemistry much more complex than the metal alloys and oxides most frequently studied yet Nd2Fe14B dominates 60% of the magnet market. The dilute non-metal boron is 6-coordinate to Iron like a subnitride, suboxide or subcarbide that then forms layers with the rare earth Nd. This inherently anisotropic structure enables high BHmax. To find an entirely new structure for an even more powerful magnet such structural features should be examined and searched for using advanced machine learning techniques that can identify millions of new complex structures like Nd2Fe14B. Combining this with advanced, high throughput computation of Bs and MagnetoCrystalline Anisotropy Energy the discovery of new Complex Magnet Materials should now be possible.