title: Interaction control between endohedral metallofullerene and metal substrate by introducing alkanethiol self-assembled monolayer.
abstract: The interaction control between endohedral metallofullerenes and a metal substrate has been demonstrated by introducing hexanethiol, octanethiol, and decanethiol self-assembled monolayers (SAMs) as the interlayer. We observe the electric properties of terbium endohedral metallofullerenes (Tb@C82) on alkanethiol SAMs with different chain lengths by scanning tunneling microscopy (STM) and spectroscopy (STS). Based on the comparison of the high-resolution STM images of a Tb@C82 molecule on hexanethiol and octanethiol SAMs, the interaction between Tb@C82 and a hexanethiol SAM is found to be larger than that between Tb@C82 and an octanethiol SAM; this is because at 68 K, the rotational states of Tb@C82 terminate only on the hexanethiol SAM. Furthermore, we find that the tunneling current-voltage characteristics of Tb@C82 on the hexanethiol SAM show the rectifying effects that are also caused by the molecular energy level shifts of Tb@C82 molecules due to the large interaction.
authors.affiliation: Department of Physical Electronics, Tokyo Institute of Technology, Tokyo 152-8552, Japan.
authors.forename: Yuhsuke
authors.initials: Y
authors.lastname: Yasutake
authors.forename: Zujin
authors.initials: Z
authors.lastname: Shi
authors.forename: Toshiya
authors.initials: T
authors.lastname: Okazaki
authors.forename: Hisanori
authors.initials: H
authors.lastname: Shinohara
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Majima
mesh_terms: D000473:Alkanes / Q000737:chemistry*; D004563:Electrochemistry; D037741:Fullerenes / Q000737:chemistry*; D008670:Metals / Q000737:chemistry*; D016252:Microscopy, Scanning Tunneling; D036103:Nanotechnology / Q000295:instrumentation / Q000379:methods*; D013438:Sulfhydryl Compounds / Q000737:chemistry*; D013499:Surface Properties; D013696:Temperature; D013725:Terbium / Q000737:chemistry*; D013997:Time Factors
chemical_list: D000473:Alkanes; D037741:Fullerenes; D008670:Metals; D013438:Sulfhydryl Compounds; D013725:Terbium