Slow magnetic domain wall motion

The speed u of slow magnetic domain wall motion has been measured as a function of applied field, H, over the interval 3.4×10−7⩽u⩽0.24 m/s at room temperature. It is found that speed does not vary exponentially with field although it may be approximated as such over restricted intervals. The data are analyzed both from the point of view of thermally activated motion and also quantum-mechanical tunneling. It is found that the formalisms of these two cases are identical. They differ only in the definition of a characteristic distance l. It is concluded that thermal activation is more likely than tunneling to be the mechanism that is operative at room temperature.