High-field magnetization of a DyFe5Al7 single crystal

The magnetization of a DyFe5Al7 single crystal with the tetragonal ThMn12-type structure was measured in pulsed fields up to 60 T along the principal axes. The compound orders ferrimagnetically at TC = 231 K and exhibits a compensation of the Dy and Fe sublattices at Tcomp = 93 K. DyFe5Al7 displays a high magnetic anisotropy of the easy-plane type, the [1 0 0] axis is the easy magnetization direction with the spontaneous magnetic moment Ms = 2.1 μB/f.u. at T = 2 K. In a field applied along the easy axis, two field-induced hysteretic transitions are observed at 30 and 53 T at T = 2 K. The critical field Hcr1 of the first transition depends strongly on temperature, whereas Hcr2 is practically temperature-independent. Above the transitions the magnetization continues to grow as a function of field, as the sublattice moments continue to rotate. To reach the full saturation (forced ferromagnetic state), fields of several Tesla higher than 60 T are required. The field dependence of magnetization along the easy [1 0 0] axis was analyzed within a model for a ferrimagnet with an anisotropic dominant sublattice. The model correctly reproduces the behavior of magnetization in a magnetic field. The intersublattice molecular field on Dy and the basal-plane anisotropy constant of the Dy sublattice have been determined.

► DyFe5Al7 is a highly anisotropic ferrimagnet. ► Magnetization of DyFe5Al7 has been studied in pulsed magnetic fields up to 60 T. ► DyFe5Al7 displays two field-induced magnetic transitions along the easy [1 0 0] axis. ► The intersublattice molecular field on Dy has been found from high-field curves. ► The basal-plane anisotropy constant of the Dy sublattice has been deduced.