నైరూప్య

The effect of lattice disorders on the behavior of domain wall interaction in fe50ni50 ferromagnetic alloy

A.R.Ali, F.Z.Ghobrial, E.Takla,K.K.Meleka

The behavior of domain wall-dislocation interaction in Fe50Ni50 alloy has been investigated in pre-annealed and quenched samples using some magnetic structure-sensitive properties. In the two samples it was found that the maximum magnetic permeability (µmax), the high field magnetic permeability (µa) and the magnetic anisotropy (K) were increased with the degree of plastic strain during the early stage of deformation, and attributed to the precipitation of FeNi3 phase during pre-annealing or after quenching from high temperature. Further increase in dislocation density in the matrix during the later stage of deformation, affects the average value of the strength of interaction between the domain wall and dislocation, thus contributes to the decrease in µa and µmax. The observed change in the magnetic anisotropy, K, with plastic strain deformation is explained in terms of themagnetic hardening of the material by dislocations. The domain wall surface energy, ã, the thickness of the magnetic domain, ä, and the exchange energy, A, of the present alloy were determined from a simple measurement of the magnetic permeability and magnetic anisotropy.