TEM INVESTIGATION OF THE MAGNETIZATION PROCESSES IN EXCHANGE-COUPLED MULTILAYER FILMS

The magnetisation reversal processes in ferromagnetically coupled mult ilayer films of (Co/NiFe/Co)Cu were investigated using Fresnel imaging . The films possess an in-plane uniaxial anisotropy and both easy and hard axis magnetism reversal were typical of ferromagnetically couple multilayer films. On application of a hard axis field, a splitting of the domain walls into two was observed. No wall transitions occurred b ut the split wall separation increased with the applied field. The for mation of 360 degrees wall loops from small domains was observed on ap plication of a hard axis field and magnetic fields up to 20H(k) were r equired to annihilate them. The magnetisation reversal on application of a field at an angle of 25 degrees to the hard axis is highly comple x and a detailed analysis of the reversal processes has been carried o ut using power spectra of fresnel images taken during magnetisation re versal.