APS March Meeting 2014
Volume 59, Number 1
Monday–Friday, March 3–7, 2014;
Denver, Colorado
Session J31: Focus Session: Beyond Graphene: Synthesis, Defects, Structure, and Properties III
2:30 PM–5:30 PM,
Tuesday, March 4, 2014
Room: 607
Sponsoring
Unit:
DMP
Chair: Arend van der Zande, Columbia University
Abstract ID: BAPS.2014.MAR.J31.4
Abstract: J31.00004 : Watching Silica's Dance: Imaging the Structure and Dynamics of the Atomic (Re-) Arrangements in 2D Glass*
3:06 PM–3:42 PM
Preview Abstract
Abstract
Author:
David Muller
(Cornell University)
Even though glasses are almost ubiquitous---in our windows, on our iPhones,
even on our faces---they are also mysterious. Because glasses are
notoriously difficult to study, basic questions like: ``How are the atoms
arranged? Where and how do glasses break?'' are still under contention. We
use aberration corrected transmission electron microscopy (TEM) to image the
atoms in a new two-dimensional phase of silica glass -- freestanding it
becomes the world's thinnest pane of glass at only 3-atoms thick, and take a
unique look into these questions. Using atom-by-atom imaging and
spectroscopy, we are able to reconstruct the full structure and bonding of
this 2D glass and identify it as a bi-tetrahedral layer of
SiO$_{2}$ [1]. Our images also strikingly resemble Zachariasen's
original cartoon models of glasses, drawn in 1932. As such, our work
realizes an 80-year-old vision for easily understandable glassy systems and
introduces promising methods to test theoretical predictions against
experimental data. We image atoms in the disordered solid [1] and track
their motions in response to local strain [2]. We directly obtain ring
statistics and pair distribution functions that span short-, medium-, and
long-range order, and test these against long-standing theoretical
predictions of glass structure and dynamics. We use the electron beam to
excite atomic rearrangements, producing surprisingly rich and beautiful
videos of how a glass bends and breaks, as well as the exchange of atoms at
a solid/liquid interface. Detailed analyses of these videos reveal a complex
dance of elastic and plastic deformations, phase transitions, and their
interplay. These examples illustrate the wide-ranging and fundamental
materials physics that can now be studied at atomic-resolution via
transmission electron microscopy of two-dimensional glasses. Work in
collaboration with: S. Kurasch, U. Kaiser, R. Hovden, Q. Mao, J. Kotakoski,
J. S. Alden, A. Shekhawat, A. A. Alemi, J. P. Sethna, P. L. McEuen, A.V.
Krasheninnikov, A. Srivastava, V. Skakalova, J. C. Meyer, and J.H. Smet.
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[1] P. Y. Huang, et al., \textit{Nano Lett.}, \textbf{12} 1081--1086 (2012).\\[0pt]
[2] P. Y. Huang et. al, \textit{Science} \textbf{342}, 224-227 (2013)
*This work was supported by the NSF through the Cornell Center for Materials Research (NSF DMR-1120296).
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2014.MAR.J31.4