Simultaneous magneto-optical Kerr effect and Sixtus-Tonks method for analyzing the shape of propagating domain walls in ultrathin magnetic wires.

The controlled nucleation and propagation of magnetic domain walls in ultrathin ferromagnetic wires, such as nanowires and submicrometer wires, is extremely important for the development of new high performance magnetic domain wall logic devices. Therefore, it is equally essential to possess adequate advanced experimental investigation techniques in order to be able to achieve a comprehensive in situ analysis of as many as possible parameters related to the domain wall propagation, e.g., wall shape besides wall velocity and position. In this paper, we report on a method developed specifically for the investigation of the shape of propagating magnetic domain walls in ultrathin magnetic wires, i.e., with the diameter of the magnetic wire in the range 100-950 nm. The newly developed experimental method is based on the simultaneous use of two full-fledged experimental techniques: the magneto-optical Kerr effect for analyzing the surface effects of the passing domain wall and the Sixtus-Tonks method for the investigation of the entire moving wall. The results obtained offer essential information about the shape of the propagating magnetic domain walls, being unique to this new method.