Simultaneous measurement of AMR and observation of magnetic domains

Anisotropic magneto resistance (AMR) sensors are widely used in daily life. Nevertheless, the influence of magnetic domains on the AMR is still not fully understood. AMR depends on the angle between applied current and the direction of the internal magnetization, which is equal to the sum of all magnetic domains. For the understanding of the AMR it is important to know the domain structure.
In this experiment Kerr microscopy is used for the observation of the magnetic domains while at the same time the AMR is measured. The investigated permalloy films are stripe patterned by Cr+ implantation. Amongst other effects the implantation leads to a lower saturation magnetization in the implanted stripes compared to the non-implanted ones.
Our measurements show a clear correlation between AMR and the magnetic domain structure. It is also possible to correlate stripe parameters to different domain types.
This work is supported by DFG grant FA316/3-2.