Magnetic microstructures of PryFe90-yB10 (y=8-11.76) nanocrystalline ribbons using magnetic force microscopy

Magnetic microstructure of melt-spun PryFe90−yB10 (y = 8, 8.5, 9, 9.5, 10 and 11.76) nanocrystalline ribbons in an as-grown state has been studied using a magnetic force microscope. The magnetic domains are characterized by dark areas adjacent to bright areas in a sub-micron scale and in random distribution. By comparing with the size of the micro-crystals measured from the TEM image, the exchange coupling effect was confirmed to exist in all the ribbons. Using the roughness analysis, the variation of the root mean-square values of the phase shifts obtained from the magnetic force images versus the content y of Pr were measured, which is very consistent with the curve of the residual induction Br versus the content y.