Ferromagnetic coupling of mononuclear Fe centers in a self-assembled metal-organic network on Au(111).
The magnetic state and magnetic coupling of individual atoms in nanoscale structures relies on a delicate balance between different interactions with the atomic-scale surroundings. Using scanning tunneling microscopy, we resolve the self-assembled formation of highly ordered bilayer structures of Fe atoms and organic linker molecules (T4PT) when deposited on a Au(111) surface. The Fe atoms are encaged in a three-dimensional coordination motif by three T4PT molecules in the surface plane and an additional T4PT unit on top. Within this crystal field, the Fe atoms retain a magnetic ground state with easy-axis anisotropy, as evidenced by x-ray absorption spectroscopy and x-ray magnetic circular dichroism. The magnetization curves reveal the existence of ferromagnetic coupling between the Fe centers.
Freie Universität Berlin, Fachbereich Physik, Arnimallee 14, 14195 Berlin, Germany.
T R
TR
Umbach
M
M
Bernien
C F
CF
Hermanns
A
A
Krüger
V
V
Sessi
I
I
Fernandez-Torrente
P
P
Stoll
J I
JI
Pascual
K J
KJ
Franke
W
W
Kuch