Indium, Tin and Antimony electro deposition from ionic liquid on copper substrate

Azal Usama Ahmed
Prof.Dr. Hadi M. A. Abood

Room temperature ionic liquids gained massive growth in recent years for their distinguished characterization like non-volatile and designed media for variable chemical and industrial application. In addition, indium metal has applications in electronic and optoelectronic devices, tin and antimony metals have good corrosion resistance and optical properties respectively. Therefore ionic liquids of the type ammonium alum: urea (1:5 mole ratio) was used as a medium to investigate the behavior and possibility of obtaining pure metal and mixture of metals from anhydrous indium chloride, tin chloride dihydrate and anhydrous antimony chloride solutions or their mixture. This investigation was carried out with the assistance of XRD, SEM, EDAX, Cyclovoltammetric, potentiostatic,AFM to determine and characterize metal reactivity and deposition metal(s) particles.Anhydrous indium chloride was found to be completely soluble up to 0.3 M in ionic liquid while suspended solutions of both tin chloride dihydrate and anhydrous antimony chloride were obtained at 0.3 M concentrations. The reduction of metal cations were in the sequence tin antimony and indium respectively showing a potential of -0.69 V, -0.8 V and -1.00 V respectively.All metals either alone or their mixture gave a nanoparticles deposition layer on copper substrate.A very smooth surface with maximum (Ra) of 34.6 nm obtained for indium andantimony after one hour from a potentiostatic deposition at -1.6 V.Meanwhile, potentiostatic deposition on copper substrate for indium, tin,antimony or their mixture of (indium and tin) and (indium and antimony) allshowed an increase of deposition quantities with time.The morphologies were also affected by deposition time and particles shapes were different from the initial deposited indium metal or its mixture with either tin or antimony at one hour from those at three hours.Bulk deposition of indium was obtained at -1.00 V while tin was obtained at 0.7Vand antimony at -0.8V.However, only a mixture of indium with tin or indium with antimony were
obtained with controlled deposited quantities by controlling the deposition potential. Thus, the deposition of indium and tin showed 80 wt.% of deposition related to tin and 20 wt.% to indium from a potentiostatic experiment at -0.8 V while at -1.1 V tin decreased to 59 wt.% and indium increased to 41 wt.% in contrast the mixture of indium and antimony showed 100 wt.% indium from potentiostatic experiment at -0.8 V while 79.5 wt.% indium and 20.5 wt.% antimony were obtained at -1.6 V.