Anisotropy Dispersion of Amorphous Soft Magnetic Films

The effects of magnetic field annealing on the anisotropy dispersion in Co-Fe-B films for use in magnetic recording heads are reported. Zero-magnetostrictive Co-Fe-B films were formed by RF diode sputtering and were then annealed, first in a rotating magnetic field, then in a direct field. Changes with annealing in the H dependence of H.¿Q/v, which corresponds to the anisotropy field distribution, and in the ß dependence of ¿Q, were determined. Among other results, direct field annealing at 100°C was found to induce a uniaxial anisotropy with relatively little dispersion.