Studies on Domain Structure of FeCoZr Films From MFM Image by Calculating the Surface Stray Field

Magnetic force microscopy (MFM) image is directly related to the field derivative distribution above the sample. It is necessary to find the real domain structure of the sample from the MFM image. In this work, the magnetic pole or charge distribution at the sample surface is calculated by deconvoluting the MFM image using the tip's Green function. The Fourier transform of the magnetic potential in the 3-D space above the sample surface can be derived from the Fourier transform of the surface charge distribution. Thus the stray field distribution of sample can be obtained since it is the gradient of the magnetic potential. Based on the stray field distribution and the magnetic properties of the sample, we can analyze the magnetic domain structure. As an example, the domain structure of FeCoZr film is studied.