Effects of discharge pressure on the properties of Ag/Ni superlattices prepared by facing-target sputtering : The 40th annual conference on magnetism and magnetic materials

1089-7550

AIP Digital Archive

Physics

Giant magnetoresistance (GMR) effect in magnetic multilayered thin films is strongly affected by interface roughness. We prepared [Ag/Ni]60 superlattices on Corning's 7059 glass substrates using a novel facing-target sputtering method and observed that the interface roughness can be controlled by varying the discharge pressure (PAr). The samples prepared at PAr≈10 mTorr exhibit sharpest interfaces, good (111) texture, and largest GMR effects (Δρ/ρs=9% at room temperature). Lower PAr promotes interface mixing while higher PAr results in much rougher interfaces and emergence of structural defects. Both cases weaken the antiferromagnetic coupling strength and thus reduce the MR effect. When PAr≥30 mTorr, we observed a further degradation of the multilayered structure. The GMR effects in these samples disappeared. Low-temperature annealing can improve the flatness of the interfaces and film structure, while higher-temperature annealing ((approximately-greater-than)300 °C) decomposes the multilayer structures. © 1996 American Institute of Physics.

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