An improved relative scaling of Volta potential differences (VPD) acquired from scanning Kelvin probe force microscopy (SKPFM) was developed by quantifying the probe work function. In corrosion studies, SKPFM has been used to identify local nobility of complex metallic systems and provide theoretical corrosion initiation sites. However, large variability in measured VPD values for metallic phases has led to controversy in their interpretation. Tracking changes of the probe work function has been shown to decrease the variability seen in SKPFM results. To quantify the work function of SKPFM probes, the measured VPD of an inert gold standard was compared to the work function theoretically calculated by density functional theory (DFT) first-principles. For proof of concept, a stainless steel sample joined by a Cu-Ag-Ti brazing material was characterized by SKPFM with three different types of probes.
© The Electrochemical Society, Inc. 2018. All rights reserved. Except as provided under U.S. copyright law, this work may not be reproduced, resold, distributed, or modified without the express permission of The Electrochemical Society (ECS). The archival version of this work was published in ECS Transactions, 85(13), 701-713. doi: 10.1149/08513.0701ecst
Efaw, C. M.; da Silva, T.; Davis, P. H.; Li, L.; Graugnard, E.; and Hurley, M.. (2018). "Improving the Relative Calculations of Volta Potential Differences Acquired from Scanning Kelvin Probe Force Microscopy (SKPFM) from Comparing an Inert Material to First-Principle Calculations". ECS Transactions, 85(13), 701-713. http://dx.doi.org/10.1149/08513.0701ecst