The magnetic structure of multiferroic RMn${}_2$O${}_5$ (R $=$ Y, Er) has been investigated by means of resonant soft x-ray diffraction. Energy, temperature, and azimuthal angle scans were performed in addition to reciprocal space maps on the magnetic reflection in the different magnetic phases of YMn${}_2$O${}_5$. We also investigated the orbital magnetic moment at the oxygen K-edge for RMn${}_2$O${}_5$ with both, R $=$ Y and R $=$ Er compositions. These moments reflect the strong hybridization between Mn 3$d$ and oxygen 2$p$ states. Experiments with applied electric fields are additionally presented, showing that the helical component of the magnetic structure in the CM phase of YMn${}_2$O${}_5$ can be reversed by the application of an electric field. However, the incommensurate magnetic reflection in the high-temperature phase is unaffected. Interestingly, this is observed only in the presence of a small electrical current, indicative of a current-induced/-enhanced switching of magnetic domains.

• Received 2 June 2011

DOI:https://doi.org/10.1103/PhysRevB.84.104416