Influence of defect thickness on the angular dependence of coercivity in rare-earth permanent magnets

Abstract

The coercive field and angular dependence of the coercive field of single-grain Nd${}_2$Fe${}_{14}$B permanent magnets are computed using finite element micromagnetics. It is shown that the thickness of surface defects plays a critical role in determining the reversal process. For small defect thicknesses reversal is heavily driven by nucleation, whereas with increasing defect thickness domain wall de-pinning becomes more important. This change results in an observable shift between two well-known behavioral models. A similar trend is observed in experimental measurements of bulk samples, where a Nd-Cu infiltration process has been used to enhance coercivity by modifying the grain boundaries. When account is taken of the imperfect grain alignment of real magnets, the single-grain computed results appears to closely match experimental behaviour.

References in corpus (1)

• Exchange coupled perpendicular media

Cited by in corpus (9)

• Grain-size dependent demagnetizing factors in permanent magnets
• Micromagnetics of rare-earth efficient permanent magnets
• Conditional physics informed neural networks
• Anisotropy of exchange stiffness based on atomic-scale magnetic properties in rare-earth permanent magnet Nd${}_2$Fe${}_{14}$B
• Thermal activation in permanent magnets
• Rare earth permanent magnets prepared by hot deformation process
• Multiscale examination of strain effects in Nd-Fe-B permanent magnets
• CuPyMag: GPU-Accelerated Finite-Element Micromagnetics with Magnetostriction
• Impact of Lattice Distortions on Magnetocrystalline Anisotropy and Magnetization in (Nd${}_{1-x}$Pr${}_x$)${}_2$Fe${}_{14}$B Alloys