Studies on compounds DyFe 3, Dy 6Fe 23 and Dy 2Fe 17 with al substitution for Fe II: magnetic investigations

Abstract

Magnetization and susceptibility measurements on pseudobinary alloys Dy 0.25 Fe 0.75− x Al x , Dy 0.207 Fe 0.793− x Al x and Dy 0.105 Fe 0.895− x Al x are reported for temperatures from 4.2 K to about room temperature. The magnetization behavior in the ordered regime indicates that the coupling scheme between the rare earth and the transition metal moments stays antiferromagnetic on Al substitution for the transition metal. All substituted materials develop respectable intrinsic magnetic hardness at cryogenic temperature. The origins of this effect are slightly different in Dy 2(Fe, Al) 17 than in all other Al-substituted materials. In the former case, the relatively high values of H c ( H c = 40 kOe at 10 K) appear to be due primarily to a state close to compensation of Dy and Fe sublattice magnetizations. The other cases of intrinsic magnetic hardness are primarily connected with partial magnetic disorder (magnetic scatter order) which in turn results in extraordinarily thin domain walls. These domain walls become pinned at obstacles of atomic dimensions.