Preparation and characterisation of Cu-Co heterogeneous alloys by potentiostatic electrodeposition

Electrodeposition in the potentiostatic mode has been used to produce Cu-Co metastable alloys. The influence of different plating parameters, such as bath composition, working electrode voltage (vs. reference) and intensity of agitation, on the composition and properties of the deposit has been investigated. A broad range of compositions (2-26 at.% Co) are obtainable. In particular, the Co content in the samples is determined mainly by the Co concentration in the bath and the electrode voltage applied during the deposition. The lack of agitation produces a deposition with a higher Co content. Experimentally obtained magnetic loops have been fitted successfully taking into account a superparamagnetic cluster size distribution. From these fits we conclude that the as deposited samples consist of superparamagnetic clusters and diluted Co atoms which do not contribute to magnetisation. These results demonstrate that electrodeposition is a promising and inexpensive preparation method for obtaining Cu-Co heterogeneous alloys with controllable and adequate properties for technological applications. (C) 2002 Elsevier Science B.V. All rights reserved.