Read-write performance of spin-filter-spin-valve heads

The magnetoresistive properties of spin-filter-spin-valve (SV) films with a synthetic pinned structure were investigated. The spin-filter-SV films equipped with a high conductive back layer enhances /spl Delta/R/R and /spl Delta/R for ultrathin free layer. Spin-filter-SV heads were fabricated and evaluated in order to verify advantages of the spin-filter structure. Spin-filter SV heads exhibit large read-back amplitude with stable asymmetry close to zero for ultrathin free layer. The bias current dependence of the asymmetry also proved a validity of the spin-filter structure. Specular-spin-filter heads utilizing the surface specular reflection achieved 6.3 mV//spl mu/m of the normalized amplitude with 0.25 /spl mu/m read-track width.