Low uniaxial anisotropy cobalt iron (COFE) free layer structure for GMR and tunnel junction heads

摘要

A multilayered free layer structure is provided for a spin valve sensor or a tunnel junction sensor wherein the net uniaxial anisotropy (H_K) of the free layer structure is low, even though some of the layers of the free layer structure have a high uniaxial anisotropy. In a preferred embodiment this is accomplished by orienting the easy axes of the high uniaxial anisotropy layers perpendicular with respect to one another so that their uniaxial anisotropies counterbalance one another leaving a low net uniaxial anisotropy which may be simply the uniaxial anisotropy of a low uniaxial anisotropy layer in the free layer structure.