NARROW TRACKWIDTH TBCO-BIASED MAGNETORESISTIVE SPIN-VALVE SENSORS

We describe the bias mechanism and MR output of a properly biased unshielded spin-valve sensor with trackwidth W of 12 mu m, height h of 3 mu m, and total stripe length L of 15 mu m. For a smaller device (L = 6 mu m, W = 2 mu m, and h = 1.5 mu m) we could no longer keep the NiFe pinned layer at 90 degrees with respect to the free layer, since the shape anisotropy became dominant, when compared with the exchange or uniaxial anisotropy field.