Ultrathin (1〜3Å) zirconium and silver film was inserted into the interface of Co/Cu artificial superlattices, and the effect on the magnetoresistance was investigated. As zirconium layer was inserted, the magnetoresistance decreased drastically and the antiferromagnetic coupling did not occur. In case of silver insertion, there is no significant change at the as-deposited state. After heat treatment, however, the antiferromagnetic coupling and the magnetoresistance ratio of silver inserted Co/Cu artificial superlattices increased more than twice. The increase of GMR is caused by the promotion of the composition profile at the interface of cobalt, which was confirmed by the ^<59>Co ferromagnetic resonance (FMR) analysis.

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Fe/[Ni_<81>Fe_<19>/Cu]_<30> multilayers with Giant Magnetoresistance (GMR) were deposited using Dual Ion Beam Sputtering (DIBS) apparatus. The change of MR characteristics by controlling the crystallite orientations and interfacial structure by means of ion bombardment to interfaces and post-annealing were investigated. In this study, it was confirmed that the spin-dependent scattering is mainly occurred at the bulk layers for Ni-Fe/Cu multilayers, but the field sensitivity is much influenced by the local structures around interfaces. Both MR ratio and field sensitivity were improved after post-annealing at temperature of 150℃. Spin Valves were prepared, in which FeMn antiferromagnetic layers were deposited under the first Ni-Fe layer to avoid oxidization of FeMn layers. FeMn layers in Spin Valve deposited on Ni-Fe underlayers whose crystallite orientations was improved by ion bombardment possessed a large exchange bias field of about 30 Oe.

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we have investigated the effects of process parameters (buffer layer material/substrate, Ar pressure, sputtering power, and thickness of Cu interlayer) on the MR (magnetoresistance) characteristics of NiFe/Cu/NiFe/FeMn spin valve structures. The effects of interface topology of spin valve multilayers on the shape of magnetoresistance curves have been discussed. The results suggest that the control of interface topology by process parameters is crucial for the improvement of MR characteristics.

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Ultra thin layers of NiFeCo and NiFe were inserted at the interfaces of Ni and Cu to form a new multilayer structure. In case of NiFe inserting layer, magnetoresistance was about 6% and saturation magnetic field was 50 Oe. In case of NtFeCo inserting layer, magnetoresistance value increased to about 8% but the saturation magnetic field was also increased to about 150 Oe. Especially, the hysteresis in R-H (resistance-magnetic field) curve increased considerably, which deteriorate the dynamic response and the bias effect.

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We have investigated the recording characteristics in combination of MR heads and a perpendicular double-layered disk. At first, perpendicular and longitudinal media were compared using the vertical type MR head on the market. Especially in the perpendicular medium, the recording characteristics were discussed in the cases of a single-pole head writing and a ring head writing. Therefore we have designed and fabricated the newly developed contact type MR/inductive heads, and they have been evaluated in order to examine the operation of the MR element and the shield in contact perpendicular recording.

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