Khaled HABIB

Materials Science and Photo-Electronics Lab., IRE Program, EBR Center, KISR, P. O. Box 24885 SAFAT, 13109 Kuwait

(Received July 26, 2013; Accepted August 21, 2013)

Shearography techniques were applied again to measure the surface resistivity/conductivity of different organic thin films on a metallic substrate. The coatings were ACE premium-grey enamel (spray coating), a yellow Acrylic lacquer, and a gold nail polish on a carbon steel substrate. The investigation was focused on determining the in-plane displacement of the coatings by shearography between 20 and 60 ℃. Then, the alternating current (AC) impedance (resistance) of the same coated samples was determined by electrochemical impedance spectroscopy (EIS) in 3.0% NaCl solution at room temperature. As a result, the proportionality constant (resistivity or conductivity = 1/surface resistivity) between the determined AC impedance and the in-plane displacement was obtained. The obtained resistivity of all investigated coatings, 40.15×106–24.6×109 Ω cm, was found in the insulator range.

Key words: surface resistivity/conductivity, organic thin films, digital shearography technique, electrochemical impedance spectroscopy (EIS), carbon steel