Research ArticleENGINEERING

Buckyball sandwiches

See allHide authors and affiliations

Science Advances  09 Jun 2017:
Vol. 3, no. 6, e1700176
DOI: 10.1126/sciadv.1700176
  • Fig. 1 Monolayer area of a buckyball sandwich.

    (A) Sandwich with both monolayered and multilayered C60 regions and (B) a higher magnification of the region labeled b. (C) Fourier transform of (B), with graphene reflections marked by red dashed lines, and some of the fullerene peaks marked in yellow. (D) Model of a monolayer C60 sandwich (top and side views).

  • Fig. 2 Dynamics of sandwiched fullerenes.

    (A) An oscillating C60 at the edge of a gap in the fullerene monolayer, over which the graphene layers are suspended. At the location indicated by the arrow, a molecule disappears and appears at least 17 times during 100 scan lines. (B) Nudged elastic band paths and energy barriers for C60 diffusion along an edge of fullerene monolayer (vertical) and from one edge of the gap to another (horizontal). (C and D) A disordered monolayer showing a void propagating from location 1 to 2, and the C60 at location 3 escaping outside the field of view between the two consecutive frames.

  • Fig. 3 Fullerene reactions.

    (A to C) A dose series of a C60 sandwich, smoothed to reduce pixel noise, Fourier-filtered to remove the graphene contribution (fig. S4), and contrast-enhanced to maximize the visibility of the C60 structures (unfiltered images and images with different contrast settings are given as figs. S5 and S6). The blue dashed lines highlight the C60 that appear to be locked in position by two-directional bonding, showing a visible internal structure and those stationary due to polymerization with yellow color. The dimers (purple) and molecules with a one-directional bond (red) still appear to be moving, obscuring their internal structure. (D) STEM image of a pair of rotating C60 [IV and V in (A)] and a simulation of a rotating (left) and a stationary (right) C60 in (E). (F) A loosely bound pair of fullerenes and a simulated C59–C59 dimer with one bond in (G) and a tightly bound pair and a simulated C59–C59 with three bonds in (H) and (I). A typical peanut dimer in (J) and an image simulation of C120 in (K). The red dashes in (D) indicate the integration width of the line profiles plotted in (D) to (K).

Supplementary Materials

  • Supplementary material for this article is available at http://advances.sciencemag.org/cgi/content/full/3/6/e1700176/DC1

    Sample morphology

    C60 Multilayers

    Stem contrast of the sandwich

    Fourier filtering

    Unfiltered stem images of the C60 sandwich

    Additional filtered views of the C60 sandwich

    Stem simulations of a C60-C60 with two bonds and singly bonded C60-C59

    fig. S1. Overview STEM micrographs, electron diffraction patterns, and Raman spectra.

    fig. S2. Structure of C60 multilayers.

    fig. S3. Moiré contrast at the edges of the C60 monolayer.

    fig. S4. Fourier filtering.

    fig. S5. Unfiltered version of the STEM micrographs of Fig. 3 (A to C).

    fig. S6. Fourier-filtered views of the rotating and fusing fullerenes.

    fig. S7. STEM simulations of merged fullerenes.

    movie S1. C60 diffusing away from a row of molecules enveloped by graphene.

    movie S2. C60 diffusing along a row of molecules enveloped by graphene.

    movie S3. Bond rotation in fullerene dimer after a 15-eV electron impact.

  • Supplementary Materials

    This PDF file includes:

    • Sample morphology
    • C60 Multilayers
    • Stem contrast of the sandwich
    • Fourier filtering
    • Unfiltered stem images of the C60 sandwich
    • Additional filtered views of the C60 sandwich
    • Stem simulations of a C60-C60 with two bonds and singly bonded C60-C59
    • fig. S1. Overview STEM micrographs, electron diffraction patterns, and Raman spectra.
    • fig. S2. Structure of C60 multilayers.
    • fig. S3. Moiré contrast at the edges of the C60 monolayer.
    • fig. S4. Fourier filtering.
    • fig. S5. Unfiltered version of the STEM micrographs of Fig. 3 (A to C).
    • fig. S6. Fourier-filtered views of the rotating and fusing fullerenes.
    • fig. S7. STEM simulations of merged fullerenes.

    Download PDF

    Other Supplementary Material for this manuscript includes the following:

    • movie S1 (.avi format). C60 diffusing away from a row of molecules enveloped by graphene.
    • movie S2 (.avi format). C60 diffusing along a row of molecules enveloped by graphene.
    • movie S3 (.mp4 format). Bond rotation in fullerene dimer after a 15-eV electron impact.

    Files in this Data Supplement: