Raman spectroscopy of cemented cobalt on zinc substrates

Micro-Raman spectroscopy is used to characterize the cemented product formed during cobalt cementation with zinc dust in zinc sulfate electrolytes, The effect of copper and antimony on the cementation process is also examined. A Raman spectrum characteristic of a basic cobalt salt or mixtures of such salts is observed. The spectrum is similar to those found for Co(OH)(2) in a ZnO matrix. The main Raman band of this salt has a frequency at 550 cm(-1). Raman mapping over a larger area, 1000 X 1000 mu m, of cemented products shows that the occurrence of this peak decreases dramatically during re-dissolution of cemented cobalt. The data indicate that a large fraction of the cemented Co2+ exists as a mixture of cobalt containing oxide and hydroxide. (C) 2000 Elsevier Science B.V, All rights reserved.