Influence of butyne-2-diol 1,4 in nickel electrocrystallization under pulse reversed current regime
(EN)
Kotzia, F
(EN)
Spyrellis, N
(EN)
Kollia, C
(EN)
The influence of the two important parameters of pulse reversed current (PRC) technique, i.e. the pulse frequency (nu) and the cathodic duly cycle (theta), and of the presence of butyne-2-diol 1,4 (BD) in a Watts type bath were examined, in nickel electrocrystallization. The fibre textures of nickel electrodeposits grown under specific conditions were studied by X-ray diffraction and the textural modifications were depicted in several diagrams. The addition of BD where the electrolyte pH is 4.5, reinforces the inhibition phenomena occurring by the application of PRC, consuming the hydrogen produced during the electrodeposition; thus it causes a pH rise near the cathode, assists the formation of Ni(OH)2 and leads to more inhibited modes of growth. A significant decrease of the pH (to 1.5) inverts the phenomenon: the additive seems to hinder the inhibitors' action, acting itself like an inhibitor of the dissolution, thus the crystallites grow more uninhibited from the dissolution products and the most free modes of growth predominate over the others.
(EN)
