Bubble-domain analogy in thin magnetic films with in-plane magnetization

The dynamical behaviour of an in-plane magnetized stripe-domain in a thin film strip is shown to be strikingly similar to that of a bubble-domain in a single-crystalline platelet. This is supported by theoretical as well as experimental evidence. In particular, several mechanisms of propagating a stripe domain by means of a local magnetic field gradient are discussed. However, from the physical point of view the "flat" and the "true" bubble differ substantially in two important respects: in the former case, (i) the wall energy plays actually no role - at least in the first approximation, and (ii) no bias field is needed to stabilize the domains (except for very narrow film strips in which a bias field must be used to stabilize the specimen's initial state of magnetic saturation). The above-mentioned similarity applies as well to the multi-domain case in a film strip, though in this case the magnetostatic stabilizing forces are obviously smaller.