Single-crystal neutron diffraction study of hexagonal multiferroic YbMnO_3 under a magnetic field

摘要

We report a single-crystal neutron diffraction study of the magnetic structure of the multiferroic compound YbMnO3, a member of the hexagonal manganite family, in zero field and under a magnetic field applied along the c axis. We propose a scenario for the zero-field magnetic ordering and for the field-induced magnetic reorientation of the Mn atom and of the two Yb atoms on distinct crystallographic sites, compatible with the macroscopic measurements, as well as with previous powder neutron diffraction experiments and results from other techniques (optical second-harmonic generation and Mossbauer spectroscopy). Our study should contribute to settling some debated issues regarding the magnetic properties of this material as part of a broader investigation of the entire hexagonal RMnO3 (R = Dy, Ho, Er, Tm, Yb, Lu, Y) family.