Magnetic anisotropy in Dy(Fe,Co)10V2

We have studied random as well as field-aligned powders of DyFe10-xCoxV2 alloys, (0≤x≤10), to investigate, by Co substitution for Fe, the effects on the saturation magnetization, anisotropy field, Curie and spin reorientation temperatures. In this system, which crystallizes with a ThMn12 structure, Co readily substitutes for iron in the whole composition range. X-ray diffraction analyses on aligned powders indicate uniaxial anisotropy at 298 K. A phase diagram for the spin arrangements in Dy(Fe,Co)10V2 system is presented. A distinctive feature we observe is that with Co substitution the axial-to-cone spin reorientation is found to shift to higher temperatures, while at the same time the cone-to-plane spin reorientation is suppressed to lower temperatures. At 290 K, the anisotropy field, HA initially increases in Dy(Fe,Co)10V2, i.e., from HA = 25 kOe (x=0) to HA = 48 kOe (x=5) and for x≥ (R18)7.5 the anisotropy becomes conical. The above results obtained from x-ray and magnetization measurements are consistent with ac susceptibility data at low temperatures. The effects of Co substitution on the anisotropic behavior in Dy(Fe,Co)10V2 system will be discussed