Investigations of crystal and magnetic properties of Dy-Fe intermetallic compounds

The crystal and magnetic properties of Dy₂Fe₁₇, Dy₆Fe₂₃, DyFe₃ and DyFe₂ intermetallic compounds are investigated with X-ray, magnetometric, ⁵⁷Fe and ¹⁶¹Dy Mössbauer effect methods. The X-ray analysis shows that investigated compounds are single phases with Th₂Ni₁₇, Th₆Mn₂₃, PuNi₃ and NgCu₂ type crystal structures, respectively. The magnetometric measurements prove their ferrimagnetic behaviour, localization of Fe magnetic moments and long range Fe-Fe exchange magnetic interactions. The crystal field effects induce magnetic anisotropy which results in local magnetic symmetry or iron atoms lower than the crystal one. This is observed by the Mössbauer effect method. The values of ¹⁶¹Dy hyperfine magnetic fields measured for investigated compounds exceed that found in metallic dysprosium due to polarization of conduction electrons by 3d-electrons of iron atoms. The weighted average value of ⁵⁷Fe hyperfine magnetic field decreases with the increase of Dy content in the compounds.