Resumo

VELEVA, L.; ESTRELLA-GUTIERREZ, M.A.; DOBROVOLSKA, Ts.  e  KRASTEV, I.. Cobalt-indium alloys electrodeposition from citrate electrolyte and spatio-temporal patterns formation. Rev. Mex. Ing. Quím [online]. 2013, vol.12, n.2, pp.345-350. ISSN 1665-2738.

Cyclic voltammetry technique was used to compare the mechanism of the deposition of In, Co and Co-In from citrate electrolytes. Samples of Co-In coatings were electrodeposited at different current densities to permit the subsequent investigation of their physicochemical characteristics. It was established a strong relation between Co-In phase composition and the electrolysis conditions. At low current densities below the limiting current only In was deposited. At higher current the alloy phase of CoIn₃ was formed, besides that of In, and minority phases were Co and Co(OH)₂. At higher current densities of about 0.8-1.5 A/dm², when intemive hydrogen evolution was observed, specific pattern (spirals, -waves, targets) were visible onto trie Co-In coating surfaces, considered as spatio-temporal structures. The pattern formation could be promoted by the specific hydrodynamic conditions close to the cathode-electrolyte interface and by the concentration fluctuation of the ionic species.

Palavras-chave : electrodeposition; cobalt-indmm alloy; cyclic voltammetry; spatio-temporal patterns; XRD; SEM-EDX.