Controlled interface profile in Sm–Co∕Fe exchange-spring magnets

In exchange-spring magnets with temperature-induced interfacial intermixing, differences in the extent of diffusion of constituent elements typically lead to local compositional changes. The authors demonstrate that adding an artificially created intermixed layer in Sm–Co∕Fe exchange-spring permanent magnets enhances the exchange coupling effectiveness without modifying the local composition of the Sm–Co layer. Element- and depth-resolved magnetization measurements verify that the diffusion extent of Sm and Co is similar across the interface.