Magneto-mechanical hysteresis damping mechanism in dual-phase iron-based alloy with zero magnetostriction

Magneto-mechanical hysteresis damping (MMHD) is usually positively correlated with their measured magnetostriction, but this correlation becomes ambiguous in negative magnetostriction and multiphase materials. This work found that even if saturated magnetostriction of Co-20Fe alloy is zero, its MMHD value can still be as high as 0.015. Analysis revealed that the MMHD correlates with phase percentages and the absolute parallel magnetostriction values of phases. In multiphase alloys, measured magnetostriction cannot be directly used to assess damping. High nonmagnetic damping in Co-15Fe alloy with fcc structure is due to distributed misfit dislocations. This research sheds light on damping mechanisms in multiphase ferromagnetic alloys.