Role of tip apices in scanning force spectroscopy on alkali halides at room temperature-chemical nature of the tip apex and atomic-scale deformations

Philipp Wagner, Adam Foster, Insook Yi, Masayuki Abe, Yoshiaki Sugimoto, Regina Hoffmann-Vogel*

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

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We have revealed processes of the tip apex distortion in the measurements of non-contact scanning force microscopy. High-spatial-resolution two-dimensional force mapping on KCl(100) surfaces for a large number of tips, seven tips, enabled us to see the complex behavior of the tip apex distortion. The tips are from Si without additional coating, but are altered by the tip-sample interaction and show the behavior of different atomic species. On the KCl(001) surfaces, the tip apex, consisting of K and Cl atoms or of Si, distorted several times while changing the distance even in a weak attractive region. There are variations in rigidity of the tip apex, but all tips distorted in the small attractive region. This complex behavior was categorized in patterns by our analyses. We compare the experimental force-distance data to atomistic simulations using rigid KCl-terminated tips and KCl-terminated tips with an additional KCl-pair designed to perform atomic jumps. We also compare the experimental force-distance data to first principles simulations using Si tips. We mainly find K-terminated tips and Si-terminated tips. We find that Si tips show only one force minimum whereas KCl-terminated tips show two force minima in line with the stronger rigidity of Si compared to KCl. At room temperature, the tip apex atoms can perform atomic jumps that change the atomic configuration of the tip apex.

Original languageEnglish
Article number035706
Number of pages10
Issue number3
Publication statusPublished - 15 Jan 2021
MoE publication typeA1 Journal article-refereed


  • scanning force microscopy
  • insulating surfaces
  • tip-sample interaction

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