Critical velocities of a twisted domain wall in very thin magnetic films

An integro-differential variant of the Slonczewski equations has been formulated so as to take into account the effect of a nonlocal magnetostatic field on the structure of twisted domain walls (TDWs) in films of very small (below DW width) thicknesses. Apart from the features specific to magnetic multilayer films, the limiting TDW velocity in this range of film thicknesses is very low (despite the small DW twist) and the TDW dynamics has a predominantly precessional character. For film thicknesses above the DW width, a maximum peak velocity determined by numerical methods has proved to be 20% higher than the well-known Walker’s value.