Compensation for the demagnetizing field in remanence measurements of perpendicular magnetic recording films

It is necessary to compensate for the demagnetizing field in remanence measurements of perpendicular magnetic recording films.In this paper,a new method of compensating for the demagnetizing field is proposed and an effective reverse field Heff is used to evaluate the dc demagnetization remanence curves,isothermal remanent magnetization curves,and the ΔM plots for perpendicular magnetic recording films.The demagnetization factor N is important for this method,and three methods are used to estimate the value of N. The results of the ΔM plots indicate that the intergranular interactions in Ba ferrite films seem to be of exchange coupling,while those in Co-Cr-Ta films are of magnetostatic interactions.