Scanning tunneling microscopy ofDy@C82andDy@

Abstract

Dy@C 82 and Dy@C 60 adsorbed on Si(111)-(7ϫ7) surface are investigated by scanning tunneling microscopy ͑STM͒ at 295 K. The Dy@C 82 molecules in the first layer are adsorbed on the Si(111)-(7ϫ7) surface without formation of islands and nucleation, and the internal structure of the Dy@C 82 molecule is first observed on the surface at 295 K. The average heights of the Dy@C 82 molecules in the first and second layers are estimated to be 7.2 and 10.8 Å, respectively, by STM. These results suggest strong interactions between the Si atoms and the Dy@C 82 molecules in the first layer. The STM image reveals that the Dy@C 60 molecule is nearly spherical, showing that the metal endohedral C 60 possesses a cage-form structure.

Molecular Orientation of Individual Lu@C82Molecules Demonstrated by Scanning Tunneling Microscopy

“…29 Using an electric image method that assumes mirror charges, 32 C 1 and C 2 are estimated as 0.092 aF and 0.19 aF, respectively, where the relative permittivity of the alkanethiol SAM is 2. 6,9,33 the distance between the STM tip and Lu@C 82 is 0.30 nm, 4 and the height of the octanethiol SAM from the Au(111) surface is 1.24 nm. 34 From eqs 2 and 3, an electron tunnels through the LUMO and HOMO levels in positive and negative sample bias voltages, respectively.…”

“…A striped structure of the Lu@C 82 molecule is observed, suggesting that thermal rotations of Lu@C 82 adsorbed on octanethiol SAMs are prevented. 6,7 The striped structure corresponds to the molecular orbital of the fullerene shell in an individual Lu@C 82 molecule. It is noted that molecular-resolution STM images of Lu@C 82 adsorbed on the heptanethiol SAMs show the same images as on octanethiol SAMs.…”

“…By utilizing STM, we can understand the intermolecular patterns and architectural parameters for realizing molecular devices. 1,[4][5][6][7][8][9][10] Endohedral metallofullerenes are one of the candidate materials for creating single molecular orientation switching devices owing to their electric dipole moment based on the electron exchange between the encapsulated metal atom and the fullerene cage. 11 For instance, in the case of a single-metal endohedral metallofullerene (M@C 82 ) (isomer I), the M@C 82 cage exhibits C 2V symmetry and possesses an electric dipole moment that is derived from the trivalent M 3+ C 82 3-electronic states.…”

Fabrication and characterization of field-effect transistor device with C2v isomer of Pr@C82

“…The high I B originates from the small mobility gap energy, E gM , of M@C 82 ; the E gM s of the C 2v isomer of Pr@C 82 and Dy@C 82 were estimated to be 0.29 and 0.20 eV, respectively, from the ρ -T plots [13,15]. Furthermore, the band gap energies, E gB s, of the C 2v isomer of Pr@C 82 and Dy@C 82 were determined to be 0.7 and 0.6 eV, respectively, from scanning tunneling spectroscopy [13,16], which were smaller than those of C 60 (1.8 -2.1 eV) and C 70 (2.2 eV) [17][18][19]. The T dependence of μ is shown in Fig.…”

Scanning tunneling microscopy/spectroscopy studies of two isomers ofCe@C82onSi(111)Fujiki1, Kubozono2, Rikiishi3 et al. 2004Phys. Rev. BSelf Cite170180View full textAdd to dashboardCite

“…Several STM studies have been performed to clarify the adsorption characteristics of metallofullerenes on various types of surfaces. [5][6][7][8][9][10][11][12] Among these studies, the interactions between metallofullerenes and well-defined Si surfaces are of much interest because of future applications, in which molecular devices and conventional Si electronics are merged.…”