Effect of Solvent and Temperature on the Anodic Oxide Films Formed on Nb in 0.1 M EDTA (Sodium Salt): Scanned Electron Micrograph Studies

Abstract

Anodization of Nb in 0.1 M EDTA (Sodium salt) has been carried out. Kinetics of anodic oxidation of Nb has been studied at a constant current density of 8 mA. cm and at room temperature. The plots of formation voltage vs. time, reciprocal capacitance vs. time and reciprocal capacitance vs. formation voltage were drawn. From these plots, formation rate, current efficiency and differential field were calculated. The Addition of solvent (Ethylene glycol) showed better kinetic results. For 20, 40, 60 and 80% aquo-glycolic media, the dielectric constant values are low leading to the marked improvement in the kinetics. The surface morphology of the anodic films was also studied by scanning electron micrographs (SEM). Kinetics was also studied at different temperatures ranging from 273 K to 333 K at a constant current density of 8 mA cm. It was observed that kinetic results were found to be increasing linearly with the decrease in temperature