• Kato, Hiroaki
• Okubo, Susumu
• Inaba, Nobuyuki
• Uda, Ryusei
• Itakura, Masaru
• Tsuchiura, Hiroki

Abstract

<jats:p> The effects of the coating surface orientation of the α-Fe soft magnetic layer on the Sm(Fe<jats:sub>0.8</jats:sub>Co<jats:sub>0.2</jats:sub>)<jats:sub>12</jats:sub> hard magnetic phase and the volume fraction of α-Fe, V<jats:sub>Fe</jats:sub>, on the maximum energy product, ( BH)<jats:sub>max</jats:sub> of exchange-coupled Sm(Fe<jats:sub>0.8</jats:sub>Co<jats:sub>0.2</jats:sub>)<jats:sub>12</jats:sub>/α-Fe nanocomposite magnet particles were micromagnetics OOMMF package was systematically investigated. The ( BH)<jats:sub>max</jats:sub> of the reference model, Sm(Fe<jats:sub>0.8</jats:sub>Co<jats:sub>0.2</jats:sub>)<jats:sub>12</jats:sub> particles without Fe layer, was 630 kJ/m<jats:sup>3</jats:sup>. In contrast, in the nanocomposite magnet particle model with soft magnetic layers on both sides of the hard magnetic phase, ( BH)<jats:sub>max</jats:sub> reached a maximum value of 657 kJ/m<jats:sup>3</jats:sup> at V<jats:sub>Fe</jats:sub> = 12% (Fe layer thickness, t<jats:sub>Fe</jats:sub> = 2 nm). In the model with α-Fe coating on the top and bottom surfaces of the hard magnetic phase, ( BH)<jats:sub>max</jats:sub> = 636 kJ/m<jats:sup>3</jats:sup> at V<jats:sub>Fe</jats:sub> = 4% ( t<jats:sub>Fe</jats:sub> = 2 nm). Furthermore, the coating of the soft magnetic phase on both sides of the hard phase particles reduces the magnitude of the demagnetizing field, H<jats:sub>d</jats:sub> of the nanocomposite magnet particles, indicating that the side coating of the soft magnetic phase is effective in increasing ( BH)<jats:sub>max</jats:sub>. These findings allow for a greater degree of freedom in the design of nanocomposite magnets by adjusting not only the V<jats:sub>Fe</jats:sub> volume fraction of the hard/soft phases but also their arrangement. </jats:p>

Topics

• nanocomposite
• impedance spectroscopy
• surface
• phase