On the bubble lattice generation in nonuniform pulse fields

The dynamic equilibrium bubble domain lattices created by nonuniform magnetic field pulses were investigated in the region of pulse amplitudes where the domain structure behaved in the most regular way. The lattice formation was found possible in a rather narrow range of the bias field values (withinHemagnetostatic calculation of the domain structure in the nonuniform field should give an appropriate theoretical formula fors1. High-speed photography has been used to record the immediate patterns of the domain structure both during a single field pulse and between the pulses. The obtained pictures made it possible to calculate the magnetic stray fields and stray field gradients when a simplified dipole model of the observed pattern was used. The attraction towards the wire has been compared with the repulsion due to the stray fields and their difference in the case of the equilibrium bubble lattice has been compared with the material coercivity term. The coercivity of the material was found to have very small influence on the translation of the domains during the process of the formation and spreading of the bubble lattice, which was attributed to the repetitive pulse component of the applied field.