The influence of plastic deformation on magnetization processes in Ni3Fe

The measurement of hysteresis loops was made in the long range ordered Ni-24.7 at% Fe single crystal which had plastically deformed, in order to study the role of dislocations in the Bloch wall movement. By tensile deformation a remarkable change was observed in coercive force Hcand maximum permeability μm; Hcincreases in proportion to the square root of plastic strain ε and becomes five times as much as before plastic deformation by 1% strain and μmdecreases to be about one fifth by the same strain, respectively. The change of Hcand μmrecovered by annealing near the transition temperature of order-disorder. It was concluded from these experimental results that the atomic disordering introduced by plastic deformation acts as an obstacle in the Bloch wall movement rather than the internal stresses around dislocations. The relationship of Hcand ε is explained quantitatively according to the modified slip induced directional order model.