Holographic interferometry in predicting cathodic deposition of metals in aqueous solution

Author(s):  
K. Habib
2008 ◽  
Vol 273-276 ◽  
pp. 283-293 ◽  
Author(s):  
Khaled Habib ◽  
K. Al-Muhanna ◽  
F. Al-Sabti ◽  
A. Al-Arbeed

In the present investigation, holographic interferometry was utilized for the first time to measure in situ the thickness of the oxide film, alternating current (A.C.) impedance, and double layer capacitance of aluminium samples during anodization processes in aqueous solution without any physical contact. The anodization process (oxidation) of the aluminium samples was carried out by the electrochemical impedance spectroscopy (EIS), in different concentrations of sulphuric acid (0.5-2.5 % H2SO4) at room temperature. In the mean time, the real-time holographic interferometric was used to measure the thickness of anodized (oxide) film of the aluminium samples in aqueous solutions. Also, mathematical models were applied to measure the alternating current (A.C.) impedance, and double layer capacitance of aluminium samples by holographic interferometry, during anodization processes in aqueous solution. Consequently, holographic interferometric is found very useful for surface finish industries especially for monitoring the early stage of anodization processes of metals, in which the thickness of the anodized film, the A.C. impedance, and the double layer capacitance of the aluminium samples in sulphuric acid (0.5-2.5 % H2SO4) can be determined in situ. Futhermore, a comparison was made between the electrochemical values obtained from the holographic interferometry measurements and from measurements of electrochemical impedance spectroscopy(EIS) on aluminium samples in sulphuric acid (0.5-2.5 % H2SO4). The comparison indicates that there is good agreement between the obtained electrochemical data from both techniques. However, there is a drastic difference between the measurement of the oxide film thickness by both techniques. The oxide film thickness of the aluminium samples in 0, 0.5, 1.0, 1.5, 2.0, 2.5% H2SO4 by the optical interferometry is in a micrometer scale. However, the oxide film thickness of the aluminium samples in 0, 0.5, 1.0, 1.5, 2.0, 2.5% H2SO4 by the E.I.Spectroscopy in a nanometer scale. This can be explained due to the fact that the E.I.Spectroscopy is useful technique to measure the electrochemical parameters and the thickness of the barrier (compact) oxide films. In contrast, the optical interferometry is found useful technique to characterize and measure the thickness of the porous oxide layer. Also, the optimum thickness of the oxide barrier film was detected to be equivalent to 0.612nm in sulphuric acid concentration of 2.5% H2SO4 by E.I. spectroscopy.


2005 ◽  
Vol 127 (8) ◽  
pp. 801-801 ◽  
Author(s):  
Noboru Tsushima ◽  
Akira Narumi ◽  
Ichiro Nakane ◽  
Takao Kashiwagi ◽  
Atsushi Akisawa

2020 ◽  
Vol 5 (2) ◽  
Author(s):  
Olusayo Olubosede ◽  
Abass A Faremi ◽  
F M Owolabi ◽  
Esther Ajiboye ◽  
Julius O Fateye ◽  
...  

In this paper, Aluminum selenide (Al2Se3) thin films are synthesized electrochemically using cathodic deposition technique in which graphite was used as a cathode while carbon as an anode. Synthesis is done at 353 K temperature from an aqueous solution of analytical grade selenium dioxide (SeO2), and Aluminum chloride (AlCl2.7H2O). Aluminum selenide thin films from a controlled medium (pH =2.0) are synthesized on fluorine doped tin oxide (FTO) substrate using varied potential voltages 1000 mV, 1100 mV, 1200 mV, 1300 mV and 1400 mV. The films are characterized for their optical properties and electrical conductivity. These various characterization reveals the successful fabrication of Al2Se3 thin films. Further investigation was done to study the effect of variation in the potential voltages.Keywords- Electrodeposition; Thin Films; Cathodic graphite; Characterization; Varied potential voltages.


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