Simultaneous occurrence of multiferroism and short-range magnetic order in DyFeO$_{\mathrm{3}}$*

We report a combined neutron scattering and magnetization study on the multiferroic DyFeO$_{\mathrm{3}}$, which shows a very strong magnetoelectric effect. Applying magnetic field along the c axis, the weak ferromagnetic order of the Fe ions is quickly recovered from a spin reorientation transition, and the long-range antiferromagnetic order of Dy becomes a short-range one. We found that the short-range order concurs with the multiferroic phase and is responsible for its sizable hysteresis. Our$ H-T $phase diagram suggests that the strong magnetoelectric effect in DyFeO$_{\mathrm{3}}$ has to be understood with not only the weak ferromagnetism of Fe but also the short-range antiferromagnetic order of Dy.