Comparison of electrochemical impedance and noise data in the frequency domain

被引:64
作者
Mansfeld, F [1 ]
Lee, CC [1 ]
Zhang, G [1 ]
机构
[1] Univ So Calif, Dept Mat Sci & Engn, Corros & Environm Effects Lab, Los Angeles, CA 90089 USA
关键词
bode plots; impedance data; noise data; frequency domain;
D O I
10.1016/S0013-4686(97)00060-1
中图分类号
O646 [电化学、电解、磁化学];
学科分类号
081704 ;
摘要
Impedance and noise data obtained for two polymer coated steel samples in sea water have been compared in the frequency domain (Bode plots). Potential and current noise data were collected simultaneously and transformed into power spectral density (PSD) plots from which spectral noise plots were obtained. Excellent agreement between impedance and noise spectra obtained with two different sets of instrumentation was observed. The noise resistance R-n is frequency-independent only if the slopes of the potential and current PSD plots are equal. In all other cases R-n is frequency dependent and therefore not a systems parameter. A limitation of the electrochemical noise technique applied to the study of polymer coatings is the fact that meaningful data can usually be collected only at frequencies below 1 Hz. Therefore features of impedance spectra indicating coating degradation and water uptake which occur at higher frequencies cannot be detected. (C) 1997 Elsevier Science Ltd.
引用
收藏
页码:435 / 438
页数:4
相关论文
共 11 条
[11]   EVALUATION OF COATING DEGRADATION WITH ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY AND ELECTROCHEMICAL NOISE-ANALYSIS [J].
XIAO, H ;
MANSFELD, F .
JOURNAL OF THE ELECTROCHEMICAL SOCIETY, 1994, 141 (09) :2332-2337