Variation of Stripe-Domain Spacing with Applied Field

Abstract

Theory has predicted that because of the exchange and demagnetizing energies, the stripe-domain spacing is a function of the amplitude of the (periodic) component of the magnetization normal to the film plane. Experimentally the stripe width was reported not to vary when the normal component of the magnetization was changed by applying a field parallel to the stripes. This disagreement, which was attributed to the coercive force of the stripes, has prevented a close comparison between theory and experiment. It has been found that the application of an oscillating field above some critical value in the plane of the film and normal to the stripes overcomes the coercivity associated with the stripes and allows the domain spacing to relax to that of a lower energy state. A change of spacing up to 50% has been observed in some Ni–Fe films. Experimental curves of the stripe width as a function of amplitude of the normal component of magnetization in the stripes are in rough agreement with the theoretical curve of Saito et al., except that his model and other one-dimensional models do not predict the change in stripe spacing to be as large as that observed. The dependence of the change in stripe spacing on the amplitude of the oscillating field and film parameters is discussed.