Local magnetic anisotropy control in NiFe thin films via ion irradiation

Abstract

A method for altering the local direction and angular dispersion of anisotropy in soft magnetic films using energetic ion irradiation is demonstrated. NiFe films 50 Å thick were irradiated with 200 keV Ar + ions to doses between 1013 and 1016ions/ cm2, while a saturating magnetic field was applied to the samples. This annealing field defined the new anisotropy direction of the irradiated areas, and the irradiation process also led to changes in the angular dispersion of anisotropy orientation, as measured by angle-dependent remanence of magnetization. By appropriate masking of films, this technique has been used to pattern samples with small "anisotropy domains." © 2002 American Institute of Physics.