The influence of ionic migration on the magnetic properties of GdIG:Al single crystals

The influence of diamagnetic cation migration on magnetic properties has been studied on single crystals of Gd3Fe5-zAlzO12with 0.3 < z < 1.4 for different quenching temperatures (Tq= 1123 K and 1473 K). The influence of Tqon the spontaneous magnetization is important in the 200 K - Tcurietemperature region. In this zone the experimental data are well interpreted on the basis of the Dionne model with modified molecular field coefficients of pure GdIG. The equilibrium distribution of Al is represented by the Van Erk model with site stabilizing energies identical to those of YIG : Al.