Magnetic force microscopy (MFM) studies of micromagnetic structures of high coercivity CoCrPt/Cr and CoCrPtB/Cr thin films

The magnetic microstructures of high coercivity CoCrPt/Cr and CoCrPtB/Cr films were investigated using magnetic force microscopy (MFM). Experiments show that the MFM technique can be used for both qualitative and quantitative description of the magnetic microstructure of high coercivity films for magnetic recording media. It was found that the magnetic microstructure was more refined for films with higher coercivity. The roughness of the magnetic images tend to decrease with increasing coercivity and decreasing media noise. Magnetic images obtained for films with ac-erased state consisted of rounded, symmetric features indicating presence of magnetic vortices. Images from samples in remanent coercivity state showed elongated transitions between regions with different magnetization direction.