TY  - JOUR
AU  - Safari, Mohammad Reza
AU  - Matthes, Frank
AU  - Ernst, Karl-Heinz
AU  - Bürgler, Daniel E.
AU  - Schneider, Claus M.
TI  - Deposition of Chiral Heptahelicene Molecules on Ferromagnetic Co and Fe Thin-Film Substrates
JO  - Nanomaterials
VL  - 12
IS  - 19
SN  - 2079-4991
CY  - Basel
PB  - MDPI
M1  - FZJ-2023-00009
SP  - 3281 -
PY  - 2022
AB  - The discovery of chirality-induced spin selectivity (CISS), resulting from an interaction between the electron spin and handedness of chiral molecules, has sparked interest in surface-adsorbed chiral molecules due to potential applications in spintronics, enantioseparation, and enantioselective chemical or biological processes. We study the deposition of chiral heptahelicene by sublimation under ultra-high vacuum onto bare Cu(111), Co bilayer nanoislands on Cu(111), and Fe bilayers on W(110) by low-temperature spin-polarized scanning tunneling microscopy/spectroscopy (STM/STS). In all cases, the molecules remain intact and adsorb with the proximal phenanthrene group aligned parallel to the surface. Three degenerate in-plane orientations on Cu(111) and Co(111), reflecting substrate symmetry, and only two on Fe(110), i.e., fewer than symmetry permits, indicate a specific adsorption site for each substrate. Heptahelicene physisorbs on Cu(111) but chemisorbs on Co(111) and Fe(110) bilayers, which nevertheless remain for the sub-monolayer coverage ferromagnetic and magnetized out-of-plane. We are able to determine the handedness of individual molecules chemisorbed on Fe(110) and Co(111), as previously reported for less reactive Cu(111). The demonstrated deposition control and STM/STS imaging capabilities for heptahelicene on Co/Cu(111) and Fe/W(110) substrate systems lay the foundation for studying CISS in ultra-high vacuum and on the microscopic level of single molecules in controlled atomic configurations.
LB  - PUB:(DE-HGF)16
C6  - 36234411
UR  - <Go to ISI:>//WOS:000867959100001
DO  - DOI:10.3390/nano12193281
UR  - https://juser.fz-juelich.de/record/916657
ER  -