Magnetostatic effects of I-bars: A unifying overview of domain and continuum results

Measured and calculated responses of Permalloy I-bar elements are compared on the basis of a proposed new classification. Small-spot Kerr effect measurements on 100 × 12 × 0.3-μm bars have permitted a detailed mapping of domain wall configurations for comparison with continuum calculations. The measured and calculated profiles of average magnetization show qualitative agreement but the local distribution of magnetization shows considerable discrepancy. Measured and calculated results of various investigators have been examined and may be conveniently classified as either of an average-magnetization type or of a pole-equivalent type. Finally, estimates of energy components in type I and type II wall configurations indicate that magnetostatic energy is dominant for the size and shape of Permalloy bars considered.