The effect of single crystalline substrates and ion-beam bombardment on exchange bias in nanocrystalline NiO/Ni80Fe20 bilayers

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Date
2013-12-23
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Institute of Electrical and Electronics Engineers (IEEE)
Abstract
Methods to modify the magnetic coercivity and exchange bias field of nanocrystalline antiferromagnetic/ferromagnetic NiO/Ni 80 Fe 20 thin films were investigated for bilayers grown using ion-assisted deposition onto different single crystalline substrates. An enhanced coercivity was found at 298 K for the films deposited on single crystalline MgO (100) and Al 2 O 3 (11-20) substrates. After field cooling the films to 50 K, the NiO/NiFe bilayer grown on Al 2 O 3 (11-20) exhibited the largest exchange bias ( - 25 Oe). The second part of the study investigated ion-beam modification of the ferromagnetic surface prior to the deposition of the NiO layer. A range of ion-beam bombardment energies (V EH ) were used to modify in situ the NiFe surface during the deposition of NiO/NiFe/SiO 2 films. Cross-sectional transmission electron microscopy showed a systematic reduction in the thickness of the NiFe layers with increasing Ar + bombardment energies attributed to etching of the surface. In addition, the bombardment procedure modified the magnetic exchange bias of the composite structure in both the as-prepared and field-cooled state. © 2013 IEEE
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Keywords
Substrates, Hysteresis, Surface treatments, Cooling, Nickel, Iron, Ion beams, Thin Films, Layers
Citation
Cortie, D. L., Shueh, C., Lai, B.-C., Pong, P. W. T., van Lierop, J., Klose, F., & Lin, K.-W. (2013). The effect of single crystalline substrates and ion-beam bombardment on exchange bias in nanocrystalline NiO/Ni80Fe20 bilayers. IEEE transactions on magnetics, 50(1), 1-4. doi:10.1109/TMAG.2013.2274654
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