SPIN-VALVE SENSORS EXCHANGE-BIASED BY ULTRATHIN TBCO FILMS

Ultrathin TbCo films are used to exchange-bias spin-valve sensors as a n alternative to the commonly used FeMn films. Magnetoresistance value s of 7.8% and sensitivities of 2.5%/Oe are demonstrated for spin-valve stripes where the pinned NiFe layer is exchange biased by a 120-angst rom thick TbCo film. The exchange field can be fine tuned by changing the TbCo layer thickness. A well-biased and linear spin-valve sensor w as fabricated, with a height of 2 mum and a trackwidth of 25 mum, wher e the free layer is biased by the sense current.