Abstrakt
The field and temperature dependence of the magnetization of a ErFe5Al7 single crystal (tetragonal crystal structure of the ThMn12-type) has been studied in magnetic fields up to 14 T. The compound is a ferri-magnet with Curie temperature T-C = 201 K and a compensation point T-comp = 34 K.
ErFe5Al7 displays easy-plane anisotropy. Anisotropy is also present in the basal plane, the easy-magnetization direction is the [100] axis with the spontaneous magnetic moment M-s = 1.28 mu(B)/f.u. at T = 2 K.
The compound exhibits field-induced magnetic transitions along the [100] and [110] axes. The transition along [100] is observed at T < 40 K and its critical field H-cr,H-100 displays complex non-monotonous temperature dependence.
Along [110] magnetization jumps occur in a very narrow temperature interval T = 31-40 K. H-cr,H-110 is a very sharp function of temperature.
Much higher fields are required to induce the transition at T < 31 K. At low temperatures strong hysteresis is observed, the coercivity is as high as H-c approximate to 2.5 T along the [100] and [110] axes at T = 2 K.