Multiferroic behaviour of YMnO_3 and YbMnO_3 epitaxial films

摘要

YMnO_3 has an antiferromagnetic (AFM) transition at 76 K with a ferroelectric (FE) transition at much higher temperature. For that reason, it is a so-called multiferroic material. Recently, anomalies in the relative dielectric permittivity in YMnO_3 near the Neel temperature were recognized. In the present study, coupling between the ferroelectric domain switching and the AFM spin ordering is demonstrated. On the other hand, magnetic field-induced ferromagnetism was recognized in a ferroelectric YbMnO_3 epitaxial film. The magnetic frustration behaviour of this ferroelectric and ferromagnetic YbMnO_3, a real multiferroic material, is also described.