NOL specular spin-valve heads using an ultrathin CoFe free layer

Abstract This paper reports the film and head performance of specular spin valves with nano-oxide layer (NOL-SPSV). A large MR ratio of 17% was obtained by using an ultrathin CoFe free layer with a high conductance Cu layer, which decreases the sense current field of a free layer and brings good soft magnetic characteristics. Prototype heads with a read track width of 0.47–0.61 μm were fabricated by using NOL-SPSV films with an MR ratio of 14–15%, H ua ∼400 Oe, and H c ∼5 Oe. High output signal voltage of 8–11 mV/μm was realized in the NOL-SPSV heads.