Low symmetry phases in rare earth iron garnets at low temperature

The magnetic anisotropy of the RE3+ ions in rare earth iron garnets (REIG) can be often described by an effective spin Hamiltonian with an exchange te nsor G representing the iron-RE anisotropic interactions. Some experimental results in DyIG and mixed Tb:YIG compounds, showing the so-called (uuw) an gular phases, are tentatively compared to the predictions of this model, es pecially in terms of the anisotropic part of the G tensor related to the cl assical cubic anisotropy constants K-1, K-2 and K-3. (C) 2000 Elsevier Scie nce B.V. All rights reserved.