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The strong (00 l ) textured Pr 12+ x Fe 82− x B 6 ( x =0, 1, 2, 3, 4) nanoflakes with high coercivity were prepared by surfactant-assisted ball milling (SABM). The thickness and length of the flakes are mainly in the range of 50−200 nm and 0.5−2 μm, respectively. A coercivity of 4.16 kOe for Pr 15 Fe 79 B 6 nanoflakes was obtained, which is the maximum coercivity of R 2 Fe 14 B (R=Pr, Nd) nanoflakes or nanoparticles reported up to now. The results of XRD and SEM for the aligned Pr 15 Fe 79 B 6 nanoflakes indicate that a strong (00l) texture is obtained and the easy magnetization direction is parallel to the surface of the flakes. The angular dependence of coercivity for aligned sample indicates that the coercivity mechanism of the as-milled nanoflakes is mainly dominated by domain wall pinning. Meanwhile, the field dependence of coercivity, isothermal (IRM) and dc demagnetizing (DCD) remanence curves also indicate that the coercivity is mainly determined by domain wall pinning, and nucleation also has an important effect. In addition, the mainly interaction of flakes is dipolar coupling. The research of coercivity mechanism for Pr 15 Fe 79 B 6 nanoflakes is important for guidance the further increase its value, and is useful for the future development of the high performance nanocomposite magnets and soft/hard exchange spring magnets. |
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