Magnetic properties and spin-reorientation transition in DyFe10−xNixSi2 compounds

The magnetic properties of DyFe10−xNixSi2 compounds with x = 0, 1, 2, 3, 4, 6, 9 and 10 have been investigated by means of X-ray diffraction and magnetic measurements. Substitution of Ni for Fe leads to a decrease in the lattice constants a, c and the unit-cell volume V. The Curie temperature reaches a maximum of 590 K at x = 2, then decreases strongly for x ≥ 2. The spin reorientations are observed for the compounds with x = 0, 1, 2 and 3. The spin reorientation temperature decreases strongly from 255 to 60 K as the Ni content is increased from x = 0 to 3. Below the spin reorientation temperature, the compounds exhibit ferrimagnetic ordering. For the Ni-rich compounds with x = 9 and 10, the magnetization of the Dy sublattice decreases strongly since the magnetization of the Dy sublattice is strongly affected by the molecular field produced by the 3d sublattice.