Spin-valves with bias compensation layer

We successfully used a bias compensation layer (BCL) for an improved bias state and asymmetry in spin-valves having a structure of Ta/NiFe/Pd₃₂Pt₁₇Mn/CoFeB₂/Cu/CoFeB ₂/NiFe/Ta/BCL/Ta. The shift of an MR response curve from a zero field is almost zero regardless of the polarity and magnitude of the sense current in an unshielded spin-valve element. Inductive/spin-valve heads were fabricated having trimmed high-Bs electroplated Ni₄₅Fe₅₅ top poles and a Ta(50 Å)/NiFe(20 Å)/PdPtMn(200 Å)/CoFeB(20 Å)/Cu(28 Å)/CoFeB(25 Å)/NiFe(20 Å)/Ta(100 Å)/NiFe(30 Å)/Ta spin-valve film. Their read/write performance was tested on a CoCr₁₉Pt₅Ta₂Nb₂ thin-film disk. The dependence of sense current on the asymmetry was small. Narrow, effective write and read track widths of 0.85 μm and 0.62 μm were measured, an output of 660 μVpp and D₅₀ of 200 kFCI were obtained