The magnetic structures and transitions of a potential multiferroic orthoferrite ErFeO3

Abstract

Rare-earth orthoferrites are very interesting due to their appealing optical and multiferroic properties. In this study, the magnetic structures and transitions of a typical rare-earth orthoferrite, ErFeO3, have been reinvestigated in detail. The spin-reorientation transition of the Fe3+ magnetic phase and the low-temperature magnetic ordering of Er3+ were observed by neutron powder diffraction. The corresponding magnetic structures have been solved anew by symmetry analysis and refinement of the diffraction results. The magnetic moments of Fe3+ align in an antiferromagnetic way along the c axis with a weak ferromagnetic component along the b axis below the Néel temperature and above the spin-reorientation transition. Below the spin-reorientation transition, the Fe3+ moments rotate into an antiferromagnetic ordering state along the b axis with weak ferromagnetic alignment along the c axis. The spin-reorientation takes place in the bc plane. The Er3+ moments align antiferromagnetically with a Cy mode below 4.5 K. For the Fe3+ moments, an additional Cx mode is induced by the ordering of the Er3+ moments. Namely, they change from GyFz mode into CxGyFz mode in the Pnma space-group setting. This study resolves the long-lasting dispute about the magnetic structure of ErFeO3 at low temperature. © 2015 AIP Publishing LLC.