Induced magnetic anisotropy and strain in permalloy films deposited under magnetic field

Field induced magnetic-anisotropy is a very important but poorly understood property. There have been many hypotheses on the origin of the phenomenon, e.g. strain, atomic pair ordering, etc., but little experimental evidence exist. This study prepares 100 nm thick Permalloy films having the field-induced-magnetic-anisotropy and carefully measure strains, i.e. interplanar distance of crystallographic (111) planes in various directions, using high power synchrotron radiation and precise Grazing Incidence X-Ray Diffraction method. The result delineates that the field-induced-magnetic-anisotropy has a strong correlation with the strain-anisotropy in the film.

► Permalloy thin films were prepared by deposition under magnetic field.
► The induced magnetic anisotropy (IMA) was formed in the thin films.
► Interplanar distance between crystallographic (111) planes was measured.
► The d(111) values were increased in proportion to the intensity of magnetic field.
► The IMA has a strong correlation with the strain anisotropy in the film.