The magnetic domain rotation in the magnetostriction process of Fe-Ga alloy

Abstract

The domain rotation process during magnetostriction in Fe-Ga rolled sheet has been clarified. The magnetic domain pattern variation with magnetic field of rolling surface was observed by magneto-optic Kerr Microscopy in-situ. According to the sample information and magnetostriction, different magnetic domain structures were constructed for different magnetization stage. In the demagnetized state, the magnetic domain structure of Fe-Ga rolled sheet was closure domain with lancet domain as supplementary domain, and when the magnetic field is larger than 8.3 kA/m the magnetic domains is lancet domains, which well explains the domain rotation process at the stage of slow magnetostriction growth. Using an equivalent stress, the magnetostriction of Fe-Ga polycrystal was simulated by an energy-based domain rotation model. The result fits well with the measured magnetostriction in rapid growth stage and saturation stage. These two models work as a complement to each other and clearly show the domain rotation process during magnetostriction.