Microstructure and magnetic properties of bulk Nd2Fe14B/α-Fe nano-composite prepared by chemical vapor deposition

The chemical vapor deposition (CVD) method was adopted to coat soft α-Fe layer on the quenched Nd13.5Fe80Ga0.5B6 ribbons. Microstructure and magnetic properties of the coated ribbons, isotropic and anisotropic Nd2Fe14B/α-Fe nano-composites were examined by means of X-ray diffraction, back-scattered electron scanning electron microscopy, field emission scanning electron microscopy and a vibrating sample magnetometer. The results showed that the CVD method was effective to introduce soft phase into the nano-composites. The microstructure and magnetic properties of isotropic/anisotropic Nd2Fe14B/α-Fe nano-composites would improve if the NdFeB ribbons were deposited with appropriate amount of soft phases. Excessive soft phase would weaken the magnetostatic coupling between soft/hard grains and deteriorate the alignment of Nd2Fe14B grains.

► Chemical vapor deposition was applied in preparing anisotropic nano-composites.
► Size and amount of soft phase in nano-composites can be controlled.
► Appropriate amount of α-Fe can enhance magnetic properties of nano-composites.
► Alignment and coupling would be restricted if excessive α-Fe were deposited.