This study provides the abundance ratio of Nd(-O) phases at the interface of Nd2Fe14B/Nd(-O) in Nd-Fe-B films with different coercivity values. The crystal structure and morphology of the Nd 2Fe14B/Nd (-O) interface were investigated by transmission electron microscopy. In the Nd-Fe-B film annealed at 350°C, the coercivity of which decreases to around 20% of the value of as-deposited film, the hcp Nd2O3 phase are existed dominantly at the surface of Nd2Fe14B phase with c-plane and non-c-plane. (In this study, the planes of Nd2Fe14B with the c-axis perpendicular or non-perpendicular to the interface are described as c-plane and non-c-plane, respectively.) On the contrary, C-Nd2O3 and amorphous phases, which were metastable phases, existed dominantly in the film after annealing at 650°C, the coercivity of which recovers to the same level of as-deposited film. The abundance ratio of the metastable phases tends to be higher at the surface of non-c-plane than at the surface of c-plane of Nd 2Fe14B phase.
- Nd oxide
- Nd-Fe-B films
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Electrical and Electronic Engineering