137203-5 , 2017-09 , American Physical Society
The existence of novel magnetic circular dichroism in core-level x-ray emission is reported. By means of circular polarization analysis, the dichroic effect of the Fe Kα1 emission spectrum is measured on an Fe single crystal. The observed dichroic effect (12%) is remarkably large, if one takes into account the small dichroic effect (about 0.5%) in the conventional K-edge absorption spectroscopy of 3d transition metal elements. The mechanism is ascribed to exchange splitting of the 2p level possessing large spin-orbit coupling. This new magnetooptical effect enables us to explore a variety of new research subjects in the magnetism of 3d transition metals and their compounds by fully utilizing its large dichroic effect, the true bulk sensitivity of hard x rays, and the element selectivity of core-level spectroscopy.