SURFACE MAGNETIC DOMAIN OBSERVATION ON THIN-GAUGED 3-PERCENT SI-FE SHEETS BY USING SCANNING ELECTRON-MICROSCOPY WITH POLARIZATION ANALYSIS (SEMPA)

The 100 mu m thick 3%Si-Fe sheets, which have magnetic induction at 10 Oe (B-10) of 1.57 to 1.98 Tesla, were prepared through induction melti ng, hot and fold rolling, and vacuum annealing processes. Scanning Ele ctron Microscopy with polarization Analysis (SEMPA) was used to image the surface magnetic domain structure of the 3%Si-Fe sheets in ultra-h igh vacuum. Two orthogonal in-plane components of the spin polarizatio n of the secondary electrons were measured to obtain the magnetic doma in images. It was observed by using SEMPA that the B-10=1.98 Tesla sam ple was almost composed of 180 degrees stripe domains which are parall el to the rolling direction. On the other hand, the Si-Fe sheet with B -10=1.57 Tesla:is composed of large 180 degrees stripe domains that ar e slanted about 30 degrees to the rolling direction. In addition, comp lex magnetic domain structures like tree and zigzag patterns were obse rved on the 1.57 Tesla sample surface.