The effect of Nd^3＋ on corrosion electrochemical behavior of copper in 3.5% (w) NaCl solution was analyzed by microelectrode array and scanning electron microscopy. The corrosion potential distribution, the impedance distribution and the carrier density distribution of corrosion product film on surface of copper were investigated. The results show that with the addition of Nd^3＋, morphology and structure of corrosion product film were changed, the film became thin, the structure of corrosion product was changed from sheet structure to granular structure and corrosion product particles were well dispersed. The presence of Nd^3＋ led the variance of corrosion potential decreased from 0.034 to 0.026 and the variance of impedance decreased from 32805 to 6940. The corrosion potential and impedance distribution tended to homogenization, which indicates that Nd^3＋ could restrain the localized corrosion. The type of semiconductor of corrosion product film on the mostly surface of copper was changed from n-type to p-type with the addition of Nd^3＋. At the same time, the variance of carrier density of corrosion product film increased from 1.89×10¹⁷ to 4.10×10¹⁷, the carrier density of corrosion product film on surface of copper tended to inhomogeneous when Nd^3＋ was added.

Key words: microelectrode array, copper, Nd^3＋, electrochemical impedance spectroscopy, Mott-Schottky analysis