Spatial spin reorientation in orthoferrites

The spatial spin reorientation (SR) in orthoferrites of the TmFe1-xMnxO3 type is considered. Characteristic of all orthoferrites the high-temperature low-ferromagnetic Γ4(Gx, Ay, F2) configuration, when the temperature decreases in certain orthoferrites (R=Sm, Er, Nd,...), changes by another low-ferromagnetic Γ2(Fx, Cy, G2) configuration (SR transition Γ4-Γ2), and in DyF6O3 - antiferromagnetic Γ1(Ax, Gy, C2) configuration (SR Morin transition Γ4-Γ1). SR transitions can be both transitions of the first type, and graded transitions of the second type with the formation of intermediate angular phases of the Γ24, Γ14, Γ12-type. The external magnetic field of H parallel b-axis decreases the region of Γ1 and Γ4 phase coexistence and shifts the Morin point, that can be detected when investigating the Γ4-Γ1 transition in DyFeO3