Effects of grain size on coercivity of combined-reaction-processed FePd intermetallics

摘要

The evolution of the microstructure and the coercivity of cold-deformed ferromagnetic Fe-Pd intermetallics with equiatomic composition during isothermal annealing at 500 and 600 deg C has been studied by X-ray diffraction, scanning and transmission electron microscopy and vibrating sample magnetometry. The deformation-processed alloys exhibit morphologically essentially equiaxed microstructures and up to about fivefold increased coercivity compared with conventionally processed bulk Llo-ordered FePd. An inverse linear relationship between the coercivity and the average grain size has been established, which for grain sizes in the range of about 0.4-1.0 mum has been attributed to a nucleation-type coercivity mechanism.