An autowave model of the spiral pattern formation in magnets located i
n a rotating magnetic field is proposed. The model is based on the ove
rdamped double sine-Gordon equation. Nucleation of spiral domains is a
ssociated with the averaged motion of domain walls in the rotating fie
ld. A vortex-type defect (Bloch line) is the core of the spiral. (C) 1
997 Published by Elsevier Science B.V.