First principles study on interfacial electronic structures in exchange-spring magnets

We study the magnetic properties of Nd2Fe14B/α-Fe multilayer systems, especially the exchange coupling between the two layers and the crystal field parameters A02⟨r2⟩ for the Nd ions located around the interfaces, based on first principles calculations. We find that the exchange coupling depends on the Miller indices of the crystallographic planes at the interface, and can be negative which favors anti-parallel alignment of the magnetizations of the hard- and soft-magnet layers.