Magnetic anisotropy of multiferroic HoMn2O5 single crystal

Magnetic properties such as magnetic susceptibility, magnetisation, and torque of HoMn2O5 multiferroic single crystal have been studied in a broad range of temperatures and magnetic fields. The crystal exhibits strong magnetic anisotropy in both paramagnetic and magnetically ordered states. The easy, middle, and hard magnetisation directions are along the b-, a-, and c-crystallographic axes, respectively, with the negative paramagnetic Curie temperatures of −10 K, −20 K, and −90 K, correspondingly. The Curie constant of 17.9 emu/mol is independent of the crystallographic directions. The second-order crystal field parameters for the Ho site are determined to be B 20 = ( 0.88 ± 0.02 ) K , and B 22 = ( 0.16 ± 0.02 ) K .