scholarly journals Passivation and activation of La0.6Sr0.4FeO3 thin film electrodes

2020 ◽  
Vol 22 (27) ◽  
pp. 15418-15426 ◽  
Author(s):  
Đorđije Tripković ◽  
Rainer Küngas ◽  
Mogens Bjerg Mogensen ◽  
Peter Vang Hendriksen
Keyword(s):  
Thin Film ◽  
Electrical Conductivity ◽  
Electrochemical Impedance Spectroscopy ◽  
Water Treatment ◽  
Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Oxygen Exchange ◽  
Conductivity Relaxation ◽  
Electrical Conductivity Relaxation ◽  
Exchange Activity

Thin La0.6Sr0.4FeO3 electrodes were investigated by electrochemical impedance spectroscopy and electrical conductivity relaxation below 600 °C. A simple water treatment was used to recover the oxygen exchange activity of the aged electrodes.

A Study of Hot Corrosion of Fe-Cr Alloys Induced by a Thin Film of Fused (Na,K)2SO4 by Electrochemical Impedance Spectroscopy

2013 ◽  
Vol 32 (5) ◽  
pp. 493-501
Author(s):  
S.N. Liu ◽  
W. Su ◽  
W.Y. Lu ◽  
Z.F. Wei ◽  
C.L. Zeng
Keyword(s):  
Thin Film ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Hot Corrosion ◽  
Electrochemical Impedance ◽  
Diffusion Flux ◽  
Electrode System ◽  
Corrosion Mechanism ◽  
Low Frequencies ◽  
Nyquist Plots

AbstractTo understand the hot corrosion mechanism of materials it is of significance to establish electrochemical measurements under a thin film of fused salts. In this paper, the hot corrosion behavior of Fe-Cr alloys containing 5, 10 and 25wt% Cr, respectively, in the presence of a fused film of 0.9Na2SO4-0.1K2SO4 (mole fraction) at 1173 K in air has been investigated by electrochemical impedance spectroscopy using a two-electrode system. The Nyquist plots for the corrosion of both Fe-5Cr and Fe-10Cr are composed of a very small semicircle at high frequencies and a line at low frequencies indicating that the corrosion is controlled by the diffusion of oxidants in the fused salt film. The alloys were severely corroded, forming a thick porous corrosion layer containing large amounts of non-protective precipitated Fe oxide particles. Conversely, the Nyquist plots for the corrosion of Fe-25Cr are composed of double capacitive loops, with significantly larger impedance values, which are associated with the formation of a protective Cr2O3 scale. Based on the experimental diffusion impedance results and the theoretic solubility and diffusion coefficient of oxygen in molten salts, respectively, a theoretical value of the diffusion flux of molecular O2 has been calculated.

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