New Magnetic Phase Transitions in DyFeO3

Spin reorientation Γ4 (Fz, Gx) → Γ2 (Fx, Gz) induced by a magnetic field parallel to the α-axis has been studied in disprosium orthoferrite at temperatures above the Morin point. A new first-order phase transition from the Γ24 (Fx, Fz, Gx, Gz) state to the Γ12 (Fx, Gy, Gz) one has been found. A phenomenological model describing spin reorientation Γ4 (Fx, Gx) → Γ2 (Fx, Gz) in DyFeO3 induced by a magnetic field is proposed.