Lateral correlation length of magnetization reversal in thin magnetic films

We determine the lateral correlation length L of the magnetization reversal process in thin magnetic films. For this purpose, we have devised an experimental system, which allows tuning of the effective disorder level by means of the local bias field distribution acting upon the magnetic film. This disorder is hereby counteracting the intergranular exchange coupling within the film, which tends to synchronize the reversal process. We observe a sharpening of the switching field distribution upon narrowing the exchange bias field distribution. Quantitative comparisons between these two quantities allow the determination of L without the need for adjustable parameters. (c) 2005 American Institute of Physics.