Evolution of magnetization reversal mechanism in Fe-Cr alloy films

A large thin film sample of FexCr1−x alloy with a composition gradient x=0.38−0.52 has been prepared by co-sputtering to investigate magnetic anisotropy and magnetization effects on reversal mechanisms. The single-phased Fe-Cr films have a bcc structure with 110 preferred orientation. Since the magnetization decreases as the Fe content is decreased and the uniaxial anisotropy energy keeps at almost constant, the uniaxial anisotropic field HK is increased. At the same time, the pinning field Hp 0 changes little since the lattice constant of Fe-Cr alloy film does not change much with the composition. Consequently, the HK can be much larger than Hp 0 for low Fe concentrations and becomes comparable with increasing Fe concentration. As a result, the magnetization reversal mechanism evolves from a mode based on the pinning and motion of domain wall to another mode based on modified Kondorsky model as the Fe content is increased. © 2006 American Institute of Physics. DOI: 10.1063/1.2357637