Dynamic behavior of domain walls in low-moment yttrium-gallium-iron garnet crystals

Measurements of domain-wall velocity, using the "bubble collapse" technique, in Y3GaxFe5-xO12 crystals with 1.0 ≤x≤1.7 show that the usual "viscous" damping model of domain-wall motion does not apply. At fields less than about 1 Oe above the threshold H0, the wall mobilities are greater than 10 3 cm/sec Oe. A few oersteds above the threshold, the field dependence of the wall velocities changes abruptly and, at higher fields, the velocities depend linearly on (H-H0)1/2. © 1971 The American Institute of Physics.