Optical Magnetoelectric Effect in the Polar GaFeO_3 Ferrimagnet

摘要

The optical magnetoelectric (ME) effect, i.e., the change of optical absorption upon the reversal of the light propagation direction, has been investigated for a polar ferrimagnet GaFeO_3. For dipole- and spin-forbidden d — d transition bands located at 1.2-2.3 eY a clear signal of the optical ME effect (Δαt ～ 3 X 10~(-3)) is observed with an applied magnetic field as low as 500 Oe and a sample thickness (t) of 50 μm. The observation of a large ME effect in the present compound suggests a possible route to magnification of this novel phenomenon for application.