High-resolution scanning tunneling microscope (STM) images of moire-structured FeO films on Pt(111) were obtained in a number of different tip-dependent imaging
modes. For the first time, the STM images are distinguished and interpreted unambiguously with the help of distinct oxygen- vacancy dislocation loops in the FeO moire structure. The experimental STM results are compared with the results of
electronic structure calculations within the DFTþUscheme for a realistic (v91 x v 91)R5.2º moire FeO unit cell supported on Pt(111) as well as with the results from previous studies. We find that one type of STM imaging mode, showing both Fe and O atoms, agrees well with simulated STM images, indicating that the simple Tersoff-Hamann theory is partially valid for this imaging mode. In addition, we identify other distinct, element-specific imaging modes which reveal a strong dependence on the specific tip apex state and likely result from specific tip-sample chemical interactions. From the present STMresults we show that several of the previously published conclusions for the FeO system have to be revisited.
Revised: October 23, 2013 |
Published: February 10, 2011
Citation
Merte L.R., L.C. Grabow, G. Peng, J. Knudsen, H. Zeuthen, W. Kudernatsch, and S. Porsgaard, et al. 2011.Tip-Dependent Scanning Tunneling Microscopy Imaging of Ultrathin FeO Films on Pt(111).Journal of Physical Chemistry C 115, no. 5:2089–2099. doi:10.1021/jp109581a