The magnetic structure of DyFeO3revisited: Fe spin reorientation and Dy incommensurate magnetic order.

High resolution and high intensity neutron powder diffraction is used to study the ground state magnetic order and the spin reorientation transition in the orthoferrite DyFeO3. The transition from the high temperaturek= 0 Γ4(GxAyFz) to the low temperature Γ1(AxGyCz) type order of the Fe-sublattice is found atTSR= 73 K and does not show any thermal hysteresis. BelowTN2= 4 K the Dy-sublattice orders in an incommensurate magnetic structure withk= [0, 0, 0.028] while the Fe-sublattice keeps its commensurate Γ1type order. DyFeO3is the first orthoferriteRFeO3to possess an incommensurate magnetic order of the rare earth sublattice under zero field conditions; an important piece of information neglected in the recent discussion of its multiferroic properties.