Static and dynamic coercivities of hard magnetic bubbles

Investigations into the translational properties of hard magnetic bubbles have revealed that both static and dynamic coercivities increase with increasing Bloch-line density. The increase of coercivity is felt to be related to a corresponding increase of wall energy density. Comparisons of experiment with theory indicate that the equations of motion require the addition of a phenomenological coercive term which is independent of Bloch-line density and which acts parallel to the applied drive field. The magnitude of this coercive term is the difference between the static and dynamic coercivities.