Impact of different Nd-rich crystal-phases on the coercivity of Nd–Fe–B grain ensembles

Aberration-corrected transmission electron microscopy, combined with atomistic simulations, has been used to study the anisotropy profiles of interfaces between metallic Nd (fcc, dhcp), Nd2O3 (hP5, cI80), NdO and the Nd2Fe14B phase. The results show that the dhcp Nd and Nd2O3-hP5 phases have a more detrimental effect on coercivity than fcc Nd, Nd2O3-cI80 and NdO. The coercivity change is rooted in distortions in the Nd2Fe14B crystal lattice; the depth and magnitude of this change is a function of orientation and type of Nd-rich phase.