Rotatable Anisotropy and Property Control of CoZr Sputtered Films

To clarify the origin of rotatable anisotropy observed in CoZr sputtered films, the effects of Ar pressure and other conditions during RF sputtering of samples on glass were studied. Increases in Ar pressure give rise to sharp jumps in film coercivity Hc and anisotropic field Hk; films with a rotatable anisotropy, as determined from magnetization curves and domain observations, had extremely high Hc and Hk values. If the film magnetostriction is positive-valued, tensile stresses in the film due to high Ar pressures will give rise to an anisotropy with the easy axis within the plane of the film.