Spin-valve read heads for tape applications

Shielded spin-valve tape heads with permanent magnet stabilization are described. Final MR of 3.5% is shown on heads with trackwidths of 5 and 9 /spl mu/m, and sensor heights of 0.5, 1.0 and 1.5 /spl mu/m. Heads are characterized on 1/2 " DLT-IV tape up to 180 kfci. For isolated transitions the heads show a PW/sub 50/ of 0.8 /spl mu/m (pulse broadening due to partial head saturation) and a baseline shift /spl sim/10% that can be positive or negative, and is related with shield remanence and transfer curve hysteresis. At 120 kfci, head output for a sense current of 3 to 4 mA is /spl sim/1 mV/sub pp/ (up to 30% of the output at 30 kfci). At high linear densities, signal loss is 0.24 dB/kfci for a 0.35 /spl mu/m shield-to-shield spacing (D/sub 50/ of 80/spl sim/100 kfci). At low linear densities the head is partially saturated, and above 60 kfci harmonic distortion is lower than -20 dB.