Processing and analysis of lift height-dependent magnetic force microscopy images of bulk uniaxial crystals

The images of the magnetic domain structure stray fields were obtained on the basal plane of Nd2Fe14B and Y2(FexCo1–x)17 (x = 0.18, 0.41) bulk uniaxial crystal samples at different tip-sample lift heights (z) using the magnetic force microscope. The automated magnetic force microscopy images evaluation method was proposed. The average extremes number per unit length n values were calculated, n(z) dependences were plotted, the analytical expression for the approximation were derived. The n0 values, related to z = 0 point were obtained by experimental data approximation with the analytical expression. The values of average domain width D and domain wall energy surface density γ were calculated using the obtained n0 values.