Ion beam sputtered spin-valve films with improved giant magnetoresistance response

A large value of giant magnetoresistance ΔR/R=9% with an exchange field Hex=350 Oe has been measured from simple NiFe/CoFe/Cu/CoFe/IrMn top spin-valve films prepared by ion beam deposition (IBD) techniques. The exchange biasing was greatly enhanced when a synthetic pinned layer, CoFe/Ru/CoFe, is used in the spin-valve structures. Apparent exchange field values in excess of 2000 Oe and ΔR/R values above 8% have been obtained in synthetic spin-valve films. These IBD spin-valve films show excellent thermal stability and they are suitable for the applications in high density magnetic recording heads.