ThMn12-type structure and uniaxial magnetic anisotropy in ZrFe10Si2 and Zr1−xCexFe10Si2 alloys

Arc-melted (Zr1−xCex)1.1Fe10Si2 alloys were found to crystallize into a pure or nearly pure ThMn12 structure for 0 ≤ x ≤ 0.6. At room temperature, the alloys exhibit ferromagnetism with an uniaxial magnetocrystalline anisotropy. Metastable ZrFe10Si2 compound possesses room-temperature saturation magnetization of at least 11 kG and Curie temperature of 325 °C; both properties slightly decrease when Ce is being substituted for Zr. The anisotropy field, on the other hand, increases with the Ce from 16.9 to 24 kOe at x = 0.6. These intrinsic magnetic characteristics as well as the absence of expensive rare-earths and Co make the compounds interesting for development of low-cost permanent magnets. At 0.7 ≤ x ≤ 0.8, the ThMn12 structure was found to co-exist with the Th2Ni17-type structure, whereas the equilibrium Th2Zn17-type structure was observed only at x = 1. Prepared under similar conditions Hf1.1Fe10Si2 alloy does not crystallize into the ThMn12-type structure.