Epitaxially grown garnet films (R,Bi)3(Fe,Ga,A1)5O12 (R = Tm, Eu, Er or Gd-Tm) with a high g-factor have been investigated. The dynamics of magnetic domain walls was studied using the high-speed photography method. In general the domain wall velocity vs pulse field have three ranges. The first range is the Walker's ones. The second (nonlinear) range occurs if the Gilbert damping parameter is α < 1. In the third range the velocity vs pulse field is linear again, but the differential domain wall mobility in this range is less than the initial (linear) ones. The initial domain wall mobility and peak velocity of domain walls in the first range vs temperature have maximum at the angular momentum compensation point. The g-factor signs below and above this point are opposite.
Vladimir V. Randoshkin,
"Magneto-Optical Garnet Films With High G-Factor", Proc. SPIE 1126, Electro-Optic and Magneto-Optic Materials and Applications, (14 December 1989); doi: 10.1117/12.961388; https://doi.org/10.1117/12.961388