On the limits of coercivity in permanent magnets

This is the final version. Available from AIP Publishing via the DOI in this recordThe maximum coercivity that can be achieved for a given hard magnetic alloy is estimated by computing the energy barrier for the nucleation of a reversed domain in an idealized microstructure without any structural defects and without any soft magnetic secondary phases. For Sm1–zZrz(Fe1–yCoy)12–xTix based alloys, which are considered an alternative to Nd2Fe14B magnets with a lower rare-earth content, the coercive field of a small magnetic cube is reduced to 60% of the anisotropy field at room temperature and to 50% of the anisotropy field at elevated temperature (473 K). This decrease of the coercive field is caused by misorientation, demagnetizing fields, and thermal fluctuations.Austrian Science Fund (FWF)New Energy and Industrial Technology Development Organization (NEDO

Mechanical Oscillations of Magnetic Strips under the Influence of External Field

By application of a magnetic field on an amorphous metallic strip, the orientation of magnetization of Weiss domains can be changed. When the strip changes its length, this effect is called magnetostriction. We simulate this effect using a finite element method. In particular we calculate the change of the mechanical resonance frequency of a magnetic platelet as a function of the applied field. This gives a quantitative model of the influence of the applied magnetic field on the effective Young’s Modulus of the material