TY - JOUR
T1 - Direct Visualization of Nearly Free Electron States Formed by Superatom Molecular Orbitals in a Li@C60Monolayer
AU - Sumi, Naoya
AU - Kuklin, Artem V.
AU - Ueno, Hiroshi
AU - Okada, Hiroshi
AU - Ogawa, Tomoyuki
AU - Kawachi, Kazuhiko
AU - Kasama, Yasuhiko
AU - Sasaki, Masahiro
AU - Avramov, Pavel V.
AU - Ågren, Hans
AU - Yamada, Yoichi
N1 - Funding Information:
This work was supported by JSPS KAKENHI Grants 20H02808 and 19K05182. This work was partly performed under the approval of the Photon Factory Program Advisory Committee (2018S2-005) and UVSOR (20-260). This work was also supported by the Russian Science Foundation (Project 19-73-10015). The authors thank the Swedish National Infrastructure for Computing (SNIC 2020-3-29) at the National Supercomputer Centre of Linköping University (Sweden) partially funded by the Swedish Research Council through grant agreement no. 2020-3-29.
Publisher Copyright:
© 2021 American Chemical Society.
PY - 2021/8/19
Y1 - 2021/8/19
N2 - Using scanning tunneling microscopy (STM) and density functional theory (DFT) calculations, we directly determine the spatial and energetic distributions of superatom molecular orbitals (SAMOs) of an Li@C60 monolayer adsorbed on a Cu(111) surface. Utilizing a weakly bonded [Li+@C60] NTf2- (NTf2-: bis(trifluoromethanesulfonyl)imide) salt makes it possible to produce a Li@C60 monolayer with high concentration of Li@C60 molecules. Because of the very uniform adsorption geometry of Li@C60 on Cu(111), the pz-SAMO, populated above the upper hemisphere of the molecule, exhibits an isotropic and delocalized nature, with an energy that is significantly lower compared to that of C60. The isotropic overlapping of pz-SAMOs in the condensed monolayer of Li@C60 results in a laterally homogeneous STM image contributing to the formation of a free-electron-like states. These findings make an important step toward further basic research and applicative utilization of Li@C60 SAMOs.
AB - Using scanning tunneling microscopy (STM) and density functional theory (DFT) calculations, we directly determine the spatial and energetic distributions of superatom molecular orbitals (SAMOs) of an Li@C60 monolayer adsorbed on a Cu(111) surface. Utilizing a weakly bonded [Li+@C60] NTf2- (NTf2-: bis(trifluoromethanesulfonyl)imide) salt makes it possible to produce a Li@C60 monolayer with high concentration of Li@C60 molecules. Because of the very uniform adsorption geometry of Li@C60 on Cu(111), the pz-SAMO, populated above the upper hemisphere of the molecule, exhibits an isotropic and delocalized nature, with an energy that is significantly lower compared to that of C60. The isotropic overlapping of pz-SAMOs in the condensed monolayer of Li@C60 results in a laterally homogeneous STM image contributing to the formation of a free-electron-like states. These findings make an important step toward further basic research and applicative utilization of Li@C60 SAMOs.
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U2 - 10.1021/acs.jpclett.1c02246
DO - 10.1021/acs.jpclett.1c02246
M3 - Article
C2 - 34378392
AN - SCOPUS:85113891090
VL - 12
SP - 7812
EP - 7817
JO - Journal of Physical Chemistry Letters
JF - Journal of Physical Chemistry Letters
SN - 1948-7185
IS - 32
ER -