Effects of a high DC magnetic field on spin reorientation in dysprosium- yttrium iron garnets at low temperatures

In this work, magnetic properties of dysprosium doped yttrium iron garnet single crystals DyxY3-xFe5O12 (1 ≤ x ≤ 3) are studied in the 2-50 K temperature range under high D.C. magnetic fields H up to 16 T. When the sample is allowed to rotate freely on itself, critical points are observed and form a critical line of second order type which increases linearly with T in the magnetic phase diagram. This line is independent of the content x delimiting a canted phase which is issued from the low symmetry angular phase occurring from the spontaneous spin reorientation below TSR (H = 0) = 14.62 K. In comparison with the free ion, the observed reduction at 0 K of the Dy3+ moments is also discussed