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Microstructure optimization to achieve high coercivity in anisotropic Nd–Fe–B thin films / W. B. Cui in Acta materialia, Vol. 59 N° 20 (Décembre 2011) 

Public ISBD [article]  in Acta materialia > Vol. 59 N° 20 (Décembre 2011) . - pp. 7768–7775 Titre : Microstructure optimization to achieve high coercivity in anisotropic Nd–Fe–B thin films Type de document : texte imprimé Auteurs : W. B. Cui, Auteur ; Y.K. Takahashi, Auteur ; K. Hono, Auteur Année de publication : 2012 Article en page(s) : pp. 7768–7775 Note générale : Métallurgie Langues : Anglais (eng) Mots-clés : Permanent  magnets  Nd–Fe–B  thin  films  Coercivity  Transmission  electron  microscopy Résumé : A high coercivity of 2.35 MA m−1 (29.5 kOe) is demonstrated using perpendicular anisotropy Nd–Fe–B films. Single layer columnar grown Nd–Fe–B thin films with a coercivity comparable with that of sintered magnets (1.11 MA m−1, 14.0 kOe) were used as the starting film. The coercivity was doubled by annealing films capped with Nd, Nd/Cu, and Nd/Ag layers. Transmission electron microscopy indicated that the Nd2Fe14B columnar grains were isolated by a Nd-rich grain boundary phase formed by diffusion of the capped layers into the grain boundaries of the polycrystalline Nd–Fe–B films. The temperature dependence of coercivity was lower than that of commercial sintered magnets. The coercivity of the Nd/Cu diffusion processed sample at 473 K was 0.979 MA m−1 (12.3 kOe), which is higher than that of Nd10Dy4Fe80B6 sintered magnets. ISSN : 1359-6454 En ligne : http://www.sciencedirect.com/science/article/pii/S1359645411006331 [article] Microstructure optimization to achieve high coercivity in anisotropic Nd–Fe–B thin films [texte imprimé] / W. B. Cui, Auteur ; Y.K. Takahashi, Auteur ; K. Hono, Auteur . - 2012 . - pp. 7768–7775. Métallurgie Langues : Anglais (eng) in Acta materialia > Vol. 59 N° 20 (Décembre 2011) . - pp. 7768–7775 Mots-clés : Permanent  magnets  Nd–Fe–B  thin  films  Coercivity  Transmission  electron  microscopy Résumé : A high coercivity of 2.35 MA m−1 (29.5 kOe) is demonstrated using perpendicular anisotropy Nd–Fe–B films. Single layer columnar grown Nd–Fe–B thin films with a coercivity comparable with that of sintered magnets (1.11 MA m−1, 14.0 kOe) were used as the starting film. The coercivity was doubled by annealing films capped with Nd, Nd/Cu, and Nd/Ag layers. Transmission electron microscopy indicated that the Nd2Fe14B columnar grains were isolated by a Nd-rich grain boundary phase formed by diffusion of the capped layers into the grain boundaries of the polycrystalline Nd–Fe–B films. The temperature dependence of coercivity was lower than that of commercial sintered magnets. The coercivity of the Nd/Cu diffusion processed sample at 473 K was 0.979 MA m−1 (12.3 kOe), which is higher than that of Nd10Dy4Fe80B6 sintered magnets. ISSN : 1359-6454 En ligne : http://www.sciencedirect.com/science/article/pii/S1359645411006331