Direct Experimental Evidence for Substrate Adatom Incorporation into a Molecular Overlayer

Mousley, Philip J.; Rochford, Luke A.; Ryan, Paul T. P.; Blowey, Philip; Lawrence, James; Duncan, David A.; Hussain, Hadeel; Sohail, Billal; Lee, Tien-Lin; Bell, Gavin R.; Costantini, Giovanni; Maurer, Reinhard J.; Nicklin, Christopher; Woodruff, D. Phil

Abstract

While the phenomenon of metal substrate adatom incorporation into molecular overlayers is generally believed to occur in several systems, the experimental evidence for this relies on the interpretation of scanning tunneling microscopy (STM) images, which can be ambiguous and provides no quantitative structural information. We show that surface X-ray diffraction (SXRD) uniquely provides unambiguous identification of these metal adatoms. We present the results of a detailed structural study of the Au(111)-F4TCNQ system, combining surface characterization by STM, low-energy electron diffraction, and soft X-ray photoelectron spectroscopy with quantitative experimental structural information from normal incidence X-ray standing wave (NIXSW) and SXRD, together with dispersion-corrected density functional theory (DFT) calculations. Excellent agreement is found between the NIXSW data and the DFT calculations regarding the height and conformation of the adsorbed molecule, which has a twisted geometry rather than the previously supposed inverted bowl shape. SXRD measurements provide unequivocal evidence for the presence and location of Au adatoms, while the DFT calculations show this reconstruction to be strongly energetically favored.

Citation

Mousley, P. J., Rochford, L. A., Ryan, P. T. P., Blowey, P., Lawrence, J., Duncan, D. A., Hussain, H., Sohail, B., Lee, T.-L., Bell, G. R., Costantini, G., Maurer, R. J., Nicklin, C., & Woodruff, D. P. (2022). Direct Experimental Evidence for Substrate Adatom Incorporation into a Molecular Overlayer. Journal of Physical Chemistry C, 126(16), 7346-7355. https://doi.org/10.1021/acs.jpcc.2c01432

• Journal Article Type: Article
• Acceptance Date: Apr 8, 2022
• Online Publication Date: Apr 19, 2022
• Publication Date: Apr 28, 2022
• Deposit Date: Feb 19, 2025
• Publicly Available Date: Feb 26, 2025
• Journal: Journal of Physical Chemistry C
• Print ISSN: 1932-7447
• Electronic ISSN: 1932-7455
• Publisher: American Chemical Society
• Peer Reviewed: Peer Reviewed
• Volume: 126
• Issue: 16
• Pages: 7346-7355
• DOI: https://doi.org/10.1021/acs.jpcc.2c01432
• Public URL: https://nottingham-repository.worktribe.com/output/41932019
• Publisher URL: https://pubs.acs.org/doi/10.1021/acs.jpcc.2c01432