Temperature dependence of coercive field of Fe-Cu and Fe-3.25-percent Si alloys

Measurements are made of the temperature dependence of the coercive field Hcof Fe-Cu alloys with up to 3 percent Cu and of Fe-3.25-percent Si alloy specimens in undeformed state and various degrees of plastic deformation. The coercive field Hcof the deformed specimens increases to a maximum with rising temperature up to about 500°C and then drops steeply at the approach of the Curie temperature. The coercive field of the Fe-Cu and the undeformed Fe- 3.25-percent Si alloy specimens drops steadily with rising temperature. The results are discussed in the light of the theoretical statements available in the literature. The behavior of the deformed specimens indicates that the change in magnetization takes place by Bloch wall movement up to about 500°C and by rotational processes above this temperature. The temperature dependence of the coercive field in the undeformed specimens is determined by the interaction of Bloch wall movement with the nonmagnetic inclusions.