On the effective mass of domain walls in magnetic-bubble materials

A set of differential equations is written to describe the structure of a 180° ferromagnetic domain wall, moving uniformly at a low speed. The Ritz model of Schlomann (1972) turns out to be a solution of these equations for an infinite crystal, which proves that his model is always a first-order approximation for thick films and large quality factor, Q. It is shown that although this first-order approximation is a rather crude one for the wall structure, it should still yield the correct wall mass.