走査型トンネル顕微鏡による珪素鋼板表面形態観察

抄録

Scanning tunneling microscope (STM) has been applied to the investigation of surface morphology of silicon steel sheets. A polished specimen was annealed in a vacuum of 10⁻⁴ Pa at 1300°C for 10 min. The detailed observations reveal that fine facet structure is formed near (001) of the α-Fe grains, and that the terrace width and the step height of the facet are determined by the misorientation angle of the grains from the [001] orientation. These results and the observed minimum step height of 0.5 nm of the terrace suggest that the (001) surface of the silicon steel sheets can be covered with a thin iron oxide film with possible orientation relationship of α-Fe(001)\varparallelFeO(001) or α-Fe(001)\varparallelFe₃O₄(001) and α-Fe[100]\varparallelFeO[110] or α-Fe[100]\varparallelFe₃O₄[110]. The change of facet structures due to lowering annealing temperature are also discussed.