Magnetization Reversal Processes in Pt/Co Multilayers Studiedby Magnetic Force Microscope

We have studied the magnetic reversal process of the magnetron sputtered Pt/Co multilayers by using magnetic force microscope with in situ bias magnetic fields. In thin films magnetic reversal is usually dominated either by domain nucleation or by domain wall motion. In our experiments, a series of magnetic images in situ captured in the same area indicates that the magnetic reversal in Pt/Co multilayers is dominated by domain nucleation, in stead of domain wall motion. In addition, the local demagnetized curve was obtained by using the bearing analysis of the domains in the series of magnetic images.