Structure and Energy of a Néel Wall by a Four-Parameter Ritz Method

A one-dimensional model with four adjustable parameters is assumed for the Néel wall separating two oppositely magnetized domains in a thin ferromagnetic film. It yields an energy which is somewhat lower than in any of the published models. Its self-consistency parameter S is not very sensitive to changes in the anisotropy constant; and, for the parameters usually used for Permalloy films, this S varies between 0.94 and 1.23, which is a necessary condition that the wall energy thus calculated is reasonably close to the true, three-dimensional minimum. It turns out that almost the same results can be obtained by choosing convenient values for two of the four parameters, and adjusting only two.