Magnetic force microscopic study of Ce2(Fe, Co)14B, and its modifications by Ni and Cu

Abstract

The domain width and domain wall energy of the Ce 2 Fe 14-x Co x B solid solution are studied for the first time in this work. The influence of Co content on these properties has been analyzed with the aid of magnetic force microscopy using diffusion couple and key alloys. The domain widths of Ce 2 Fe 14-x Co x B decreased with increasing Co content at about 0.02 μm per 1 at.% Co. In Ce 2 Fe 14-x Co x B, phase shift, domain width and saturation magnetization are related in a way that lower average domain width is associated with higher phase shift and higher saturation magnetization. The highest domain wall energy of Ce 2 Fe 14-x Co x B is measured as 31.7 erg/cm 2 after dissolving 14 at.% Co (x=2.38). The effects of Ni and Cu on the domain width and domain wall energy of Ce 2 Fe 14-x Co x B (x=1.02) are also studied and reported using response surfaces. The domain width and domain wall energy of this solid solution increased after doping with 1 at.% Ni at constant Co content of 6 at.%, measuring 1.39 μm for domain width and 33.4 erg/cm 2 for domain wall energy. Both properties were determined as 0.71 μm and 18.6 erg/cm 2 , respectively, after doping with 0.8 at.% Cu, while keeping Co content constant at 6 at.%. When Ce 2 Fe 14-x Co x B (x=1.02) is doped with both Ni (1 at.%) and Cu (0.8 at.%), the domain width and domain wall energy measured 0.99 μm and 33.8 erg/cm 2 , respectively.