A double peak of the coercive force near the compensation temperature in the rare earth iron garnets

The behavior of the coercive force, Hc, of ferrimagnets near the compensation temperature, Tcomp, for polycrystalline rare earth iron garnets R3Fe5O12 (R = Gd, Tb, Dy, Ho and Er) has been studied in detail. The present experimental results have verified the double peak in Hc near Tcomp for these rare earth iron garnets R3Fe5O12. For Dy3Fe5O12, the experimental values are Tcomp = 224 K, Hc (max) = 600 Oe at Tcomp ±δ K andδ ≈ 10 K. The two peaks of Hc arise at 214 and 232 K. The appearance of the double peak of Hc is an intrinsic and characteristic property for R3Fe5O12. The results can be understood on the basis of a simple model. The hysteresis loop in the magnetization is caused by rotation of single domain under the influence of crystalline anisotropy rather than domain wall displacements of the multi-domain structure. The rare earth ion behaves as superimposed paraprocess under the influence of weak exchange field produced by iron sublattices and an external magnetic field