M. Siadat-Cheraghi, S. R. Allahkaram, Z. Shahri,
Volume 12, Issue 1 (3-2015)
Abstract
Pure cobalt coatings were electrodeposited on copper substrate by means of direct electric current in a
chloride solution at different current densities in the range of 10-70 mA cm
-2
. The surface morphology and
microstructure were investigated via X-ray diffraction analysis and scanning electron microscopy. Corrosion behavior
of cobalt coatings was also studied in a 3.5 wt% NaCl solution using potentiodynamic polarization and impedance
spectroscopy techniques. The results showed that corrosion resistance of deposits was strongly influenced by the
coating’s morphology. Co deposit obtained in lower current densities exhibited the highest corrosion resistance, due
to their lower grain boundaries and so the least density of active sites for preferential corrosion attacks
Noor Alhuda Hassan, Zainab Jaf, Hanaa Ibrahem, Mohammed Hamid, Hussein Miran,
Volume 21, Issue 0 (3-2024)
Abstract
This work reports the influence of Cu dopant and annealing temperature on CdOx thin films deposited on glass substrates by spray-pyrolysis method. The Cu doping concentrations were 0, 0.46, and 1.51 at% with respect to the CdOx undoped material. Then, the fabricated films were subjected to annealing process at temperature of 450°C. X-ray diffraction (XRD) examination confirms that the as-deposited films show a cubic crystallographic structure with high purity of CdO in the annealed films. It was found that the (111) peak is the most predominant diffraction orientation in the surveyed samples. At the microscopic scale, AFM machine was operated to quantify the three important parameters of the mean roughness (Ra), rms value (Rq), and z scale. These parameters hold highest values for the sample with 0.46 at% of Cu. Finally, reflectance, absorbance, transmittance and other optical parameters dielectric measurements were comprehensively analyzed. Our evaluation of optical band gaps for the studied samples reveals that the synthesized films have direct band gap character with the fact that the rise in the Cu contents in the as-deposited films lead to lessen the band gap values. In contrast, annealing process results in raising the band gap.
