Effects of Tensile Stress on Total Loss of Single Crystals of 3% Silicon-Iron

The variation of total loss under the tensile stress applied along the near [001] direction has been measured on the single crystals with (110) [001] orientation of 3% silicon-iron. It has been found that the total loss was greatly decreased with an application of stress. This effect is more remarkable when the orientation is more perfect or the permeability at 10 Oe is higher. An influence of surface roughness and grain size on this effect was also investigated. The large reduction in total loss with an application of stress can be qualitatively explained by a change of domain structure and a domain wall pinning taking the degree of orientation into account. It is also pointed out that the glass film by which a tensile stress is induced on the materials is very useful in improving the total loss of grain-oriented silicon-iron with high permeability.