Narrow track current-perpendicular-to-plane spin valve GMR heads

We have investigated the performance of dual spin valve heads in the current-perpendicular-to-plane (CPP) geometry on dynamic electrical tests (DET) and quasi-static tests (QST). Shielded CPP reader and stitched pole writer composite heads were fabricated. A various physical read track width and area of the dual spin valve element were deliberately obtained in the range of 41-175 nm and 0.0034-0.022 μm², respectively. Materials used for the CPP dual spin valve are Co₉₀Fe₁₀, Ni₈₀Fe₂₀, Cu, Ru, Ta, and Pt₅₀Mn₅₀, which are common in industrial current-in-plane (CIP) spin valves. The shape and smoothness of QST transfer curve, readback waveform, micro-track, and full-track profiles of the narrow read track CPP heads are essentially just the same as those of CIP spin valve. A track-average-amplitude of 0.6 mV was obtained at the bias current density of element around 100 MA/cm² in the CPP head with the physical read track width of 47 nm. Overall reader resistance of the CPP heads at head gimbals assembly (HGA) level was in the range of 10-35 Ω and proved to be well appropriate.