Selective deposition of a gadolinium(III) cluster in a hole opening of single-wall carbon nanohorn

Hashimoto et al. 10.1073/pnas.0400596101.

Supporting Information

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Supporting Figure 3
Supporting Movie 1
Supporting Movie 2
Supporting Figure 4

Supporting Figure 3

Fig. 3. Sealing the openings of oxNH580. (a) TEM images of intact oxNH580 treated with C₆₀. Fullerene molecules fill the entire interior of the nanohorns. (Scale bar, 5 nm.) (b) TEM images of GdoxNH580 treated with C₆₀. Several Gd clusters are in the nanohorns, but (virtually) none of C₆₀ molecules. (Scale bar, 20 nm.) oxNH, oxidized carbon nanohorn.

Supporting Figure 4

Fig. 4. EELS of GdoxNH580 indicating the presence of Gd(III) and oxygen atoms in the cluster. (a) Blue line shows EELS of a Gd-cluster contained in a nanohorn as observed by the STEM/EELS machine of 3 × 3 Å area resolution. Peaks at 150 eV, 300 eV, and 540 eV correspond to the N-edge of Gd, the K-edge of C, and the K-edge of O, respectively. The red line shows EELS of a nanohorn without a cluster. The data indicate that the cluster consists of Gd and oxygen atoms. (b) EELS due to the M-edge of Gd. The blue line shows EELS of a Gd-cluster-containing nanohorn, and the green line shows the one of pure Gd₂O₃ as a reference. The fine structure of the M-edge of the Gd cluster is identical to the one of the reference trivalent Gd. Note that a core-level shift of 3 to 4 eV is expected for the lanthanoid M-edge, depending on the valence states, and hence the observed matching demonstrates that the cluster contains only trivalent Gd atoms (1). STEM, scanning transmission electron microscopy; EELS, electron energy-loss spectrometry.

1. Suenaga, K., Iijima, S. Kato H. & Shinohara, H. (2000) Phys. Rev. B 62, 1627.

Supporting Movie 1

Movie 1. TEM movie (total observation time of ≈1 min) of the Gd cluster in oxNH420 (GdoxNH420). Four Gd atoms are seen to rotate on the edge of the hole located on the side of the NH. The square arrangement of the four metal atoms appears to be retained during this movement indicating stronger interaction among the metals (through oxygen atoms; cf. Fig. 4) than that between the hole edge and the metal atoms.

Supporting Movie 2

Movie 2. TEM movie (total observation time of ≈1 min) of the Gd cluster in oxNH580 (GdoxNH580). The metal atoms in the cluster exhibit Brownian-like movement under the TEM observation conditions. However, the cluster itself does not move away from the region where it is attached. One Gd atom attached to the hole in the bottom left moves along the hole edge. In a few larger clusters in the interior of the NHs (top left and bottom right), the metal atoms move within each cluster, but the size and the location of the clusters do not change.