Observation of buried magnetic domains in grain-oriented electrical steel

Bulk-sensitive microscopic measurements of buried magnetic domains are reported. Utilizing a new magneto-optical effect in the hard X-ray regime, referred to as X-ray magnetic circularly polarized emission, the internal transverse domains in a grain-oriented electrical steel sheet are unambiguously observed. This allows the lateral shapes of the transverse domains to be successfully visualized. In addition, we discuss the magnetic domain structure of the supplementary domains below the surface from measurements performed at several pairs of incident and exit angles.