Magnetooptical study of thickness dependences of magnetization reversal of thin NiFe and Co films

Abstract Effect of thickness on the magnetic structure formation and the elementary events of magnetization reversal processes in ferromagnetic (FM) NiFe and Co films were investigated using the magnetooptical indicator film technique. It was found that there are two stages of the reversal along the easy direction in the thicker films. It occurs by first quasi-uniform magnetization rotation and then by nucleation and growth of new domains with unusual non180° domain walls. It was shown that reversal of the thinnest films is controlled by new domain nucleation inside them, whereas the thicker film reversal is done by same process at the edges. It was proposed that thinnest film magnetization reversal is determined by inhomogeneities at the FM/substrate interface.