We fabricated a model interface system, which consised of a Nd2Fe14B layer with Dy overlayers, in order to study the relationship between the microstructure near the interface and the coercivity. The coercivity H c of the 1-μm-thick Nd-Fe-B films with a Dy overlayer was enhanced by thermal diffusion of Dy atoms from the film's surface into the Nd-Fe-B layer. The Nd-Fe-B/Dy films annealed at 700 °C showed a significant increase in the H c of up to about 17 kOe. The maximum increase in the value of the coercivity ΔH c of the annealed films with a Dy overlayer was approximately 13 kOe. The XRD measurement suggested the existence of rare-earth oxides (NdO and Dy2O3) in the Dy-coated films with high value of the ΔH c.
- Thin films