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EFFECT OF THE ANOMALOUS CODEPOSITION ON THE COMPOSITION AND DEPTH PROFILE OF NANOSCALE Ni-Co-Cu/Cu MULTILAYERS
L. Péter1, J. Pádár1, E. Tóth-Kádár1, I. Bakonyi1, K. Vad2, Z. Berényi2
1) Research Institute for Solid State Physics and Optics, Hungarian Academy of Sciences, H-1525 Budapest, P.O.Box 49., Hungary
2) Institute of Nuclear Research of the Hungarian Academy of Sciences, Debrecen, Hungary
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Ni-Co-Cu/Cu multilayers have been deposited by using electrolytes of various Ni:Co ratio with a fixed metal
salt concentration. The composition diagram of the deposits shows that the codeposition of the nickel and cobalt
takes place in the so-called "anomalous" way, similarly to the case when both the electrolyte and the deposit are
void of copper. When the deposition rate of the magnetic layers is well below the mass transport limited rate, the
Ni:Co ratio in the magnetic layer is independent of the current density. However, the Ni:Co ratio in the deposit is
a function of the layer thickness, indicating that the depletion of the electrolyte affects the deposition process.
The higher the layer thickness, the more the Ni:Co ratio in the multilayer approaches the composition of the deposit
obtained by direct current. The thickness dependence of the layer composition led us to the conclusion that there is
a composition gradient in the magnetic layer along the growth direction. This latter statement was evidenced by a
secunder neutral mass spectrometric (SNMS) study.
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