Synergistic effect of additives on electrodeposition of copper from cyanide-free electrolytes and its structural and morphological characteristics

Electrodeposition of acid copper plating on mild steel substrate is tedious due to the galvanic displacement reaction ofcopper on mild steel.This can be avoided by using a proper complexing agent,because the complexing agent tuned the potential ofnoble direction to less noble direction by complex formation.In this paper,environment friendly electrodeposition of copper fromnon-cyanide electrolyte using sodium gluconate as complexing agent was investigated in alkaline medium.The effects of additivessuch as1,2,3-benzotriazole,sodium lauryl sulphate,PEG8000and saccharin were studied.These additives are found to reduce thegrain size,grain boundaries and improve surface morphology of the copper deposits.Also they improve the throwing power of thedepositing electrolytes and hardness of deposits.The electrodeposited copper coatings were characterized by X-ray diffractiontechnique.XRD results indicate that the electrodeposited copper shows polycrystalline and face centered cubic structure.The crystalsize was calculated by XRD and AFM analysis.Among these additives studied,the mixture of benzotriazole and sodium laurylsulphate acts as the best additive.A uniform pore-free surface observed under SEM and AFM results reveal the grain refining broughtabout by the additives.

Microstructure and crystallographic characteristics of nanocrystalline copper prepared from acetate solutions by electrodeposition technique

Methane sulphonic acid is an alternative electrolyte for conventional sulphuric acid for copper deposition.Theelectrodeposition of copper from eco-friendly acetate-based electrolytes consisting of copper acetate,sodium acetate and methanesulphonic acid was dealt.Thamine hydrochloride(THC),saccharin and4-amino-3-hydroxynaphthalene1-suphonic acid were used asadditives in depositing electrolytes.The cathode current efficiency was calculated using the Faraday’s law.Metal distrbution ratio ofthe solutions was determined using Haring?Blum cell.These additives impact the surface morphology of deposited copper films bydowngrading,the grain size was analyzed by scanning electron microscopy(SEM)and X-ray diffiraction technique.XRD patternacquired for electrodeposited copper film shows polycrystalline and face centered cubic structure(FCC).The crystal size of thecopper film was calculated using the Debye?Scherrer’s equation.The crystal size revealed that deposits produced from additivecontaining electrolytes exhibited the lowest grain size.Texture coefficient analysis studies revealed that all copper film deposits arepolycrystalline and the crystals are preferentially oriented and parallel to the surface.A uniform and pin-hole free surfacemorphology and grain refining were brought about by the additives.

Autocatalytic deposition of copper from modified electrolytes and its characteristics

The electroless deposition process of copper plating consisting of TEA and EDTA as complexing agents,paraformaldehyde as reducing agent,and 2-mercaptobenzothiozole as stabilizer and gelatin and animal glue as additives was investigated.The stability of the electroless copper solution was monitored by measuring the absorbance of the solution with a UV-Visible spectrophotometer and the solution was quite stable up to 15 h.The adhesion of copper films on mild steel foil was assessed by standard bend test and exhibited good adhesion.The XRD results indicate that the copper films have a(111) texture.Moreover,the additives suppress the predominant(111) plane crystal growth and increase the rate of(220) texture crystal growth.The crystal size of the copper films was calculated using the Scherrer formula from the predominant peak.SEM and AFM studies reveal that these two additives modify the crystal structure,grain size and surface morphology of the copper films.The cyclic voltammetry studies reveal that the additives are adsorbed on the electrode surface and inhibit the rate of deposition.Potentiodynamic polarization and electrochemical impedance studies reveal that the deposits produced in the presence of additives display higher corrosion resistance.

Development of black Ni-Co alloy films from modified Watts electrolyte and its morphology and structural characteristics

The electrodeposition of black Ni-Co alloy film from Watts nickel solution and the effects of benzotriaozole and imidazole as the additives were studied. The electrolyte consists of NiSO4, NiC12, H3BO3, COSO4 and KNO3. The cathode current efficiency and the throwing power of the solution and the film adhesion to the mild steel metallic foil were determined by standard methods. The crystal structure, lattice parameter, crystal orientation and crystal size were analyzed by X-ray diffraction （XRD）. Moreover, the surface morphology and elemental composition of the black Ni-Co alloy films were analyzed by scanning electron microscopy （SEM） and energy dispersive X-ray spectroscopy （EDX） techniques. The darkness of the black films increases with increasing the incorporation of Co ion into the films. The XRD studies reveal that the black Ni-Co alloy films exhibit Ni （11 l） as the preferred orientation.