| AVS 61st International Symposium & Exhibition | |
| 2D Materials Focus Topic | Wednesday Sessions |
| Session 2D+EM+NS+SS+TF-WeM |
| Session: | Novel 2D Materials |
| Presenter: | Christin Büchner, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Germany |
| Authors: | C. Büchner, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Germany L. Lichtenstein, Lawrence Berkeley National Laboratory M. Heyde, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Germany H.-J. Freund, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Germany |
| Correspondent: | Click to Email |
For the first time, the structure of an amorphous network is imaged in real space.[1] Through a thin film approach, silica is made accessible for investigation with scanning tunneling microscopy (STM) and atomic force microscopy (AFM). Physical vapor deposition with subsequent annealing is employed to create an atomically flat bilayer of SiO2, supported on a Ru(0001) single crystal. Atomic positions of oxygen and silicon can be visualized, as well as ring structures with their distributions and local neighborhoods. All atomic species on the surface can be directly assigned with chemical sensitivity imaging.[2] This allows for statistical analysis of the building units, comparing amorphous to crystalline regions, as well as experiment to theory. Pair correlation functions of the 2D film structure are set against diffraction data of bulk silica, revealing very similar bond distributions.
Coexisting crystalline and amorphous areas allow imaging of a topological transition region.[3] The understanding of glassy structures gained from these experiments is the starting point for more in-depth structural investigations[4], but also for investigating thin films with modified composition. Al-doping or Fe-doping can be employed to create 2D-Aluminosilicates or 2D-Clays, respectively.[5] Adsorption properties of the film can be probed using single metal atoms which migrate through the film, exhibiting ring-size-selectivity.[6]
[1] L. Lichtenstein, et al., Angew. Chem., Int. Ed. 51, 404 (2012)
[2] L. Lichtenstein, et al., J. Phys. Chem. C 116, 20426 (2012)
[3] L. Lichtenstein, et al., Phys. Rev. Lett. 109, 106101 (2012)
[4] C. Büchner, et al., Z. Phys. Chem., DOI: 10.1515/zpch-2014-0438 (2014)
[5] J. A. Boscoboinik, et al., Angew. Chem. Int. Ed. 51, 6005 (2012)
[6] W. E. Kaden, et al., Phys. Rev. B 89, 115436 (2014)