Single Domain Wall Propagation at Low Fields

We have studied the domain wall propagation at low fields regime in thin glass-coated microwire of composition $Fe_{77.5}Si_{7.5}B_{15}$. It is shown, that power law describes domain wall dynamics at low fields. Such behaviour results from the interaction of the propagating domain wall with the defects present in the material. At high fields, the domain wall mobility becomes negative. This can be explained as a result of domain structure relaxation. The exponent q from power law, which determines the domain wall shape, has a value of 0.19 for both cases, without applied stress and with applied stress of 20 MPa. This means, that domain wall shape is flexible in both measurements.