Domain wall mobility in orthoferrite platelets with non-perpendicular magnetocrystalline anisotropy

Domain wall mobility has been investigated in yttrium orthoferrite platelets with different angle α between the c crystal axis and normal to the surface. Depending on the wall orientation with regard to the a crystal axis, the latter in each case located within the platelet plane, skew or normal domain wall was created by the external gradient field /perpendicular or paralel to this axis respectively/. The measurements were carried out using a technique proposed by Shumate. The obtained mobilities for skew and normal walls show a significant difference. The observed effect has been explained on the base of simple theoretical model which predicts the following relation between the skew and normal wall mobilities (μsand μnrespectively) depending on the angle . The obtained experimental results are in good agreement with this model if only the effective angle α between the wall and normal to the surface has been taken into account, since in experiment the wall was not paralel to the ac crystal plane. A remarkable increase of the dynamic coercivity for the skew wall has been also observed experimentally.