Effects of scratching on losses in 3-percent Si-Fe single crystals with orientation near

The effects of scratching perpendicular to the [001] direction on losses were studied as a function of the tilt angle of the [001] out of the crystal surface β both with and without tensile stress in 3-percent Si-Fe single crystals. The reduction of the total losses by scratching becomes larger with decreasing β. The total losses of scratched samples further decrease with the application of tensile stress parallel to the [001] direction. Observations of domain structure showed that scratching causes a decrease in 180° main domain wall spacings and also the occurrence of reverse subdomains in the vicinity of the scratch. It was found that the total losses of scratched specimens are lower than those of unscratched samples for equal 180° main domain wall spacing observed in the demagnetized state. This may be because the losses of scratched samples are influenced by the dynamic behavior of reverse subdomains in addition to the function of 180° domain wall displacements, The variation of dc hysteresis loss by scratching is very small. This may be caused by the effect of the new domain configuration at the scratch line, which weakens the domain wall pinning due to free poles or internal stress caused by scratching.