Spin-valve sensors with domain control hard magnet layers

Abstract

We have fabricated unshielded narrow-track NiFe/Cu/NiFe/FeMn spin-valve sensors with a height of 2 /spl mu/m and a track-width of less than 2 /spl mu/m using CoCrPt hard magnets (4/spl pi/Mr=5500 G, Hc=1000 Oe) as a domain control layer. Barkhausen noise was completely suppressed by a longitudinal biasing field from the CoCrPt layers. The bias state was improved by applying a strong ferromagnetic exchange coupling field of 30 Oe between the free and pinned NiFe layers through a 14 /spl Aring/-thick Cu interlayer. We have also fabricated shielded CoCrPt magnet-biased spin-valve read heads with a track-width of 1.7 /spl mu/m. The heads had no Barkhausen noise and very low crosstalk noise.