Amorphous Networks at the Atomic-Scale: Comparing Two-Dimensional Silica and Germania
ORAL
Abstract
Recently, new insight into the atomic-scale structure of amorphous networks was established through the development of 2D thin-films of known glass formers using scanning tunneling microscopy (STM) in combination with density functional theory (DFT) [1-3]. Here we present a study of two prominent glass-formers, silica and germania, using high-resolution ultra-high vacuum STM to characterize structure. Both SiOx and GeOx films were grown on Ru(0001) by physical vapor deposition and subsequent annealing in oxygen, yielding either crystalline or amorphous structures. STM images reveal a hexagonal network with domain boundary structures in atomically flat monolayer films for both glass formers, with germania showing a greater variety of structures. Bilayer films provide for the development of amorphous structure and similar ring structures are seen for both materials. A few exceptions to the structural analogy are seen experimentally and described by DFT, which predicts a stronger interaction with the metal support for germania. This work reveals commonalities and species dependency for glassy structures.
[1] L. Lichtenstein et al. Angew. Chem. Int. Ed. 51, 404 (2012)
[2] A. Lewandowski et al. Phys. Rev. B. 97, 115406 (2018)
[3] A. Lewandowski et al. J. Phys. Chem. C, accepted (2018)
[1] L. Lichtenstein et al. Angew. Chem. Int. Ed. 51, 404 (2012)
[2] A. Lewandowski et al. Phys. Rev. B. 97, 115406 (2018)
[3] A. Lewandowski et al. J. Phys. Chem. C, accepted (2018)
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Presenters
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Kristen Burson
- Physics Department, Hamilton College
- Physics, Hamilton College