Magnetization dependent demagnetization characteristic of rare-earth permanent magnets

Rare earth elements and permanent magnets (invited)

Rare earth (RE) magnets have become virtually indispensible in a wide variety of industries such as aerospace, automotive, electronics, medical, and military. RE elements are essential ingredients in these high performance magnets based on intermetallic compounds RECo5, RE2TM17 (TM: transition metal), and RE2TM14B. Rare earth magnets are known for their superior magnetic properties—high inducti...

Correlations in rare-earth transition-metal permanent magnets

Rare-earth Permanent Magnets: New Magnet Materials and Applications

The introduction of rare-earth permanent magnets based on samarium-cobalt in about 1970, and neodymium-iron-boron magnets in the mid-nineteen eighties, has ushered in a new era in hard magnetic materials. This has resulted in a dramatic improvement in permanent magnet performance, with neodymium-iron-boron (Nd2Fe14B) magnets having a magnetic energy product up to an order of magnitude greater t...

Radiation-Induced Demagnetization of Nd-Fe-B Permanent Magnets

Introduction The Advanced Photon Source (APS), as well as other third-generation synchrotron light sources, uses permanent magnets in the insertion devices to produce x-rays for scientific research [1,2]. When placed in a high-energy storage ring, these permanent magnets are subjected to irradiation from synchrotron radiation, high-energy bremsstrahlung, and bremsstrahlung-produced neutrons. Pr...

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

The coercive field and angular dependence of the coercive field of single-grain Nd2Fe14B 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-pinn...