Quantitative analysis of 90° closure domains occurring by compressive stress in Fe3%Si(110) Steels

The 3-D structures of the 90° closure domains in demagnetized Fe3%Si(110) steels occurring by the compressive stress were quantitatively analyzed using domain theory. The dependence of the compressive stress and the thickness in the 90° closure domains were evaluated using the proposed closure domain model with the 90° domain width. It was revealed that the 90° closure domain width decreases with an increase in compressive stress and steeply increases with a decrease in compressive stress. Moreover, our calculations predict that the critical compressive stress for the occurrence of the closure domains increase with the decrease in specimen thickness. The results suggest that when the thickness becomes thinner, enhancement of local compressive stress may be needed to refine 180° basic domains along the rolling direction. The validity of the calculation was confirmed by comparison with the past data and our presented domain observations by photoemission electron microscopy combined with X-ray magnetic circular dichroism.