Magnetic-field orientation and coercivity

The relationship between the coercive force and the angle of the applied field of an infinite magnetic medium containing a planar defect have been analyzed. A domain-wall pinning dominated coercivity was assumed and the spatial dependence of the magnetization in the direction normal to the plane of the defect was taken into account. The results show that the coercivity must be about two orders of magnitude smaller than the anisotropy field for the inverse cosine curve to be a good approximation. Some of the results with experimental work on Fe77Nd15Bs are compared. In addition, the existence of a decrease in the domain-wall pinning coercivity as a function of the angle between the applied magnetic field and the anisotropy for certain ranges of parameters—a behavior previously thought to have only occurred in the angular dependence of a nucleation dominated coercivity—is shown.