(Invited) Magnetic Field Assisted Electrodeposition of Topographically and Chemically Structured Copper-Nickel Deposits

Abstract

Electrodeposition under the influence of magnetic field has sparked the interest of researchers for decades. The beneficial effects of homogenous magnetic fields on electrodeposition enable increased deposition rates as well as smoother deposits.[1] These effects have been intensively studied and attributed to magnetohydrodynamic forces. Conversely, several questions remain unanswered with respect to the beneficial influence of heterogeneous magnetic fields.[2] There, local convection allows structuring of deposit morphologies; however, it has not yet been reported if magnetic gradients can be used to induce local compositional changes.[3] Here, we investigate the opportunity to induce both, topographic and chemical structuring of electrodeposits by magnetic gradients.For this purpose, potentiostatic deposition of CuNi films is carried out on an Au coated glass slide using a sulphate-based aqueous electrolyte. An iron wire template is magnetised by a permanent magnet and placed below the working electrode to apply well defined, high magnetic gradients during electrodeposition. The obtained Cu-Ni deposits are analysed by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). The results of these measurements reveal that the deposited film topography follows the distribution of superimposed magnet field gradients and that a local compositional change of the deposits is possible. Thus, our results open up a new path to control the local morphology of complex deposits structures and other properties of films by magnetic gradient assisted electrodeposition. References (1) Uhlemann, M.; Tschulik, K.; Gebert, A.; Mutschke, G.; Fröhlich, J.; Bund, A.; Yang, X.;Eckert, K. Eur. Phys. J. Spec. Top. 2013, 220, 287–302.(2) Mutschke, G.; Tschulik, K.; Weier, T.; Uhlemann, M.; Bund, A.; Fröhlich, J.Electrochimica Acta 2010, 55, 9060–9066.(3) Karnbach, F.; Uhlemann, M.; Gebert, A.; Eckert, J.; Tschulik, K. Electrochimica Acta2014, 123, 477–484