Induced magnetic anisotropy in metallic glasses irradiated by swift heavy ions

Effects of swift heavy ion irradiation on ferromagnetic amorphous Fe81B13.5 Si3.5C2 ribbons were investigated by transmission and conversion electron F e-57 Mossbauer spectrometry. Irradiation was found to induce changes in the magnetic texture depending on the ion energy and the corresponding project ed range. The magnetic anisotropy tends to become randomly distributed in t he case of the highest ion energy as the result of the strong level of elec tronic excitations induced throughout the sample. A perpendicular magnetic anisotropy was evidenced in the case of implantation of the ion beam inside the amorphous alloys. The origin of the induced perpendicular magnetic ani sotropy was interpreted in terms of magnetoelastic effects due to strong st resses generated by the reaction of the nonirradiated region to the anisotr opic deformation of the irradiated amorphous material. (C) 2001 American In stitute of Physics.