Micromagnetic modeling of thin-film recording heads

As recording heads become smaller to achieve higher recording densities, their domain structure increasingly influences their performance. Due to the presence of closure domains in the head, for track widths the order of 1 μm, the available head flux becomes limited and the asymmetry in the flux geometry is increased. To study the problem, this paper presents some micromagnetic calculations on thin-film recording heads. The model computes the domain variations in the head when a field is applied for both permalloy and iron-nitride. It is found that the flux asymmetry is small for small fields, increases to a maximum, and finally disappears at saturation. Possible designs that could reduce this effect are discussed