Correlation of magnetic domains and magnetostrictive strains in Terfenol-D via magnetic force microscopy

Abstract

Local evolution of magnetic domain structures in Terfenol-D under variable magnetic fields is characterized using magnetic force microscopy and the resulting magnetostrictive strains parallel and perpendicular to the applied magnetic field are simultaneously measured. It is found that both magnetic domain structure and magnetostrictive response depend upon the loading history and a substantial change in magnetic domains is observed for Terfenol-D under opposite magnetic field, resulting in notable asymmetry in magnetostrictive strain. The technique will be useful in characterizing the evolution of magnetic domains for a wide range of ferromagnetic materials under an external field.