Magnetic properties of Sc-substituted erbium iron garnet single crystals in high magnetic field

Magnetic properties of garnet single crystals Er₃Fe_5-zSc_zO₁₂ (z=0.10 and 0.30) are reported under high magnetic field up to 264 kOe in the 2–320 K temperature range. Below the compensation temperature T_comp (71 and 52 K for z=0.10 and 0.30, respectively), in the spontaneous state, the magnetic anisotropy is very weak for z=0.10 and more important for z=0.30. The “easy” axis is [100] for both Sc concentrations as in pure ErIG. These results are compared to Faraday rotation anisotropy. From the analysis of the temperature dependences of the spontaneous magnetizations, the molecular field coefficient N_dc related to the Fe–Er superexchange interactions has to be, as are N_dd and N_ad, a function of z. In the high magnetic field and at low temperature, the onset of the usual canted magnetic phase takes place for H applied parallel to the “easy” [100] axis for both concentrations, whereas an unusual behavior is observed for z=0.30 and H parallel to [111] direction: below 30 K, three temperature dependent field induced transitions are observed. © 1999 American Institute of Physics.