Effects of Compressive Stress on the Magnetostrictive Characteristics of Sm-Fe-B Films

A set of Sm-Fe-B films with different compressive stresses were prepared on substrates with different prestrains by ion beam spurting deposition (IBSD). The influence of compressive stress on the magnetic anisotropy and the magnetostriction in sputter-deposited amorphous Sm-Fe-B films were investigated. Films affected by compressive stress all show in-plane anisotropy and easy axis along the direction of stress is induced in the film with compressive stress increasing. Magnetostriction of Sm-Fe-B films affected by compressive stress is improved in low magnetic field while saturation of magnetostriction decreases slightly. At the same time, the magnetostriction rises rapidly in low field measured in a field parallel to the film plane at room temperature with the growth of compressive stress. It is also found that the magnetic domain component which is perpendicular to the film plane increases on a small scale, though the magnetic domain or the magnetic domain component parallel to film plane still exist dominantly.