High-resolution Kelvin probe microscopy in corrosion science: Scanning Kelvin probe force microscopy (SKPFM) versus classical scanning Kelvin probe (SKP)

Rohwerder, Michael; Turcu, Florin

doi:10.1016/j.electacta.2007.03.016

Cited by 318 publications

(214 citation statements)

References 53 publications

Supporting

Mentioning

211

Contrasting

Unclassified

Order By: Relevance

“…The Volta potential indicates the relative tendency of metals to corrosion and can help to assess the severity of localized corrosion in alloys with complex microstructures [42,[44][45][46]. In a galvanic couple, the phase with higher electrochemical nobility has typically higher Volta potentials and usually acts as the cathode, whereas that with lower Volta potentials acts as the anode [47,48].…”

Section: Volta Potential Microscopymentioning

confidence: 99%

Volta Potential Evolution of Intermetallics in Aluminum Alloy Microstructure Under Thin Aqueous Adlayers: A combined DFT and Experimental Study

et al. 2018

View full text Add to dashboard Cite

In this work, first-principle density functional theory (DFT) was used to calculate the work function and Volta potential differences between aluminum alloy matrix and two intermetallic phases (Mg 2 Si and Al 2 Cu) with varying surface terminations as a function of adhering monolayers (ML) of water. The calculated data were compared with experimental local Volta potential data obtained by the scanning Kelvin probe force microscopy (SKPFM) on a commercial aluminum alloy AA6063-T5 in atmospheric environments with varying relative humidity (RH). The calculations suggest that the surface termination has a major effect on the magnitude and polarity of the Volta potential of both intermetallic phases (IMP's). The Volta potential difference between the IMP's and the aluminum matrix decreases when the surface is gradually covered by water molecules, and may further change as a function of adhering ML's of water. This can lead to nobility inversions of the IMP's relative to the aluminum matrix. The measured Volta potential difference between both IMP's and their neighboring matrix is dependent on RH. Natural oxidation in ambient indoor air for 2 months led to a nobility inversion of the IMP's with respect to the aluminum matrix, with the intermetallics showing anodic nature already in dry condition. The anodic nature of Al 2 Cu remained with the introduction of RH, whereas Mg 2 Si became cathodic at high RH, presumably due to de-alloying of Mg and oxide dissolution. The DFT calculations predicted an anodic character of both IMP's in reference to the oxidized aluminum matrix, being in good agreement with the SKPFM data. The DFT and SKPFM data were discussed in light of understanding localized corrosion of aluminum alloys under conditions akin to atmospheric exposure.

show abstract

Section: Volta Potential Microscopymentioning

confidence: 99%

Volta Potential Evolution of Intermetallics in Aluminum Alloy Microstructure Under Thin Aqueous Adlayers: A combined DFT and Experimental Study

et al. 2018

View full text Add to dashboard Cite

show abstract

“…[28][29][30] After electrochemical hydrogen loading and necessary cathodic polarization of the steel sample, the initial surface oxides are completely reduced to iron affecting the Fermi level alignment. As recorded CPD is, due to calibration on Cu/Cu 2 + -electrochemical system, directly linked to electrochemical potentials, 26) the explanation for a decrease of measured CPD can be easily given by Nernst equation. For the uncharged specimen with native oxide layer, the CPD is governed by following reaction: With E 0 describing the standard electrode potential, R the ideal gas constant, T the temperature, F the Faraday constant and a the activities of both reduced and oxidized species.…”

Section: Resultsmentioning

confidence: 99%

“…Advantages of this technique are arising from the very sensitive, non-destructive measurement principle, the possibility to investigate surface processes as well as the possibility to link the measured work function or rather contact potential difference (CPD) with an electrochemical potential. 26) In this manner, influence of microstructural defects in steel, , respectively. By controlling atmosphere composition and humidity during consecutive Kelvin probe measurements, the influence of oxygen concentration on the hydrogen discharging process was investigated, revealing interaction between surface oxides and hydrogen.…”

Section: Introductionmentioning

confidence: 99%

Rolling Direction Dependent Diffusion Coefficients of Hydrogen in Ferritic Steel by SDCM Charging and SKP Probing

2016

View full text Add to dashboard Cite

“…The oxygen concentration in the KP chamber was monitoredwithanoxygensensor withalowerdetectionlimitof 1%.As the chamber, which is gastight except for a gas outlet backpressure valve, is constantly flushed with nitrogen, it can be assumed that the real oxygen concentration is much lower than 1%. In order to enable comparison to electrochemical potentials, the system was calibratedbefore measurementby probinganelectrochemical system with known potential, which was in this case the liquid surface of a saturated CuSO 4 solution in a Cu crucible [35].…”

Section: Methodsmentioning

confidence: 99%

Challenges in hydrogen quantification using Kelvin probe technique at different levels of relative humidity

Burgstaller

Schimo

Hassel

2017

J Solid State Electrochem

View full text Add to dashboard Cite

Kelvin probe-based contact potential measurements were conducted with in situ electrochemical hydrogen loading of a Pd membrane with a thickness of 100 μm. The theoretical basis of diffusion coefficient calculation based on measured response time of potential drop, arising from hydrogen arriving at the detection side of the Pd membrane, was discussed. In situ hydrogen loading was also utilized for insertion of different amounts of hydrogen into the Pd sample while monitoring the resulting contact potential difference changes. Measurement of contact potential difference at different final values of hydrogen concentration in the Pd membrane was performed at various atmospheric conditions, focusing in this work on increasing relative humidity (4 to 85% rH). Moreover, the effect of humidity changes on hydrogen effusion kinetics at room temperature and low oxygen content (<1%) was studied.

show abstract

High-resolution Kelvin probe microscopy in corrosion science: Scanning Kelvin probe force microscopy (SKPFM) versus classical scanning Kelvin probe (SKP)

Cited by 318 publications

References 53 publications

Volta Potential Evolution of Intermetallics in Aluminum Alloy Microstructure Under Thin Aqueous Adlayers: A combined DFT and Experimental Study

Volta Potential Evolution of Intermetallics in Aluminum Alloy Microstructure Under Thin Aqueous Adlayers: A combined DFT and Experimental Study

Rolling Direction Dependent Diffusion Coefficients of Hydrogen in Ferritic Steel by SDCM Charging and SKP Probing

Challenges in hydrogen quantification using Kelvin probe technique at different levels of relative humidity

Contact Info

Product

Resources

About