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Microstructure and coercivity in La-coated Nd2Fe14B thin films

Authors :
Daisuke Ogawa
H. Ishikawa
J. Fukuda
Hiroaki Kato
Kunihiro Koike
Masaru Itakura
Source :
AIP Advances, Vol 7, Iss 3, Pp 035301-035301-9 (2017)
Publication Year :
2017
Publisher :
AIP Publishing, 2017.

Abstract

We investigated La-coated Nd2Fe14B thin film magnets by scanning/transmission electron microscopy to clarify the coercivity enhancement mechanism in Nd-Fe-B permanent magnets. The coercivity of La-coated film magnets was increased from 8.5 to 15 kOe by post-annealing. The fcc-LaOx layer was epitaxially grown on [001]-oriented Nd2Fe14B fine grains with a crystallographic orientation relation of Nd2Fe14B (001)[110] || LaOx (111)[112¯], both in the as-deposited and post-annealed films. STEM-EDS elemental analysis revealed that the only difference caused by post-annealing was the O content in the LaOx layer, which increased from 15 to 35 at.%. These results suggest that the magnetocrystalline anisotropy of the Nd ions, which were reduced at the surface of Nd2Fe14B, would be recovered by the presence of O, leading to a remarkable increase in the coercivity.

Details

ISSN :
21583226
Volume :
7
Database :
OpenAIRE
Journal :
AIP Advances
Accession number :
edsair.doi.dedup.....25679d81188f83602fcbe7e962d71cb0
Full Text :
https://doi.org/10.1063/1.4977966