Interface stability and composition profile of electrodeposited nanolayers

László Péter 1Imre Bakonyi 1Enikő Tóth-Kádár 1Kálmán Vad 2Gábor L. Katona 2

1. Hungarian Academy of Sciences, Research Institute for Solid State Physics and Optics (SZFKI), Konkoly Thege M. út 29-33, Budapest H-1121, Hungary
2. Institute of Nuclear Research of the Hungaryan Academy of Sciences (ATOMKI), Bem tér 18/C, Debrecen, Hungary, Debrecen 4001, Hungary

Abstract

The sharpness of layer interfaces and a homogeneous component distribution within each layer are a key issue in the electrodeposition of nanostructures from magnetic alloy films to multilayers.

When alloys are used to build up multilayers with a thickness in the nanometer range, the codeposition of the constituent metals usually lead to a composition gradient within the layer along the growth direction. The compostion change is a result of the mixed control of depositon by diffusion and activation. This change in the local composition can have a significant impact on the magnetic properties of the layer. The local composition evolution can be calculated from the change in the total composition as a function of the layer thickness. Also, it can be followed by direct depth profiling methods. We used secondary neutral mass spectrometry to observe the depth profile of various metallic multilayers. A comparison of the indirect and direct local composition analysis results will be presented.

In metallic multilayers, the composition of the individual layers may change already during the electrodeposition process due to the dissolution of the more active material. In this case, component intermixing occurs at the layer interfaces, and the layer thicknesses will significantly deviate from the nominal ones. This can be clearly observed both from direct imaging methods like TEM and indirect methods like composition analysis and magnetic properties. An easy-to-follow electrochemical optimisation process is suggested to identify the optimum conditions for the electrodeposition of metallic multilayered materials.

 

Presentation: Oral at E-MRS Fall Meeting 2007, Symposium D, by László Péter
See On-line Journal of E-MRS Fall Meeting 2007

Submitted: 2007-05-11 09:37
Revised:   2009-06-07 00:44