Scientific REPORTS | 7: 16544 | DOI:10.1038/s41598-017-16321-5
Tabby graphene: Dimensional
magnetic crossover in uorinated
T. L. Makarova
, A. L. Shelankov
, A. I. Shames
, A. A. Zyrianova
, A. A. Komlev
G. N. Chekhova
, D. V. Pinakov
, L. G. Bulusheva
, A. V. Okotrub
& E. Lähderanta
Tabby is a pattern of short irregular stripes, usually related to domestic cats. We have produced Tabby
patterns on graphene by attaching uorine atoms running as monoatomic chains in crystallographic
directions. Separated by non-uorinated sp
carbon ribbons, sp
-hybridized carbon atoms bonded
to zigzag uorine chains produce sp
interfaces and spin-polarized edge states localized on both
sides of the chains. We have compared two kinds of uorinated graphite samples C
, with x near
to 1 and x substantially below 1. The magnetic susceptibility of C
(x < 1) shows a broad maximum
and a thermally activated spin gap behaviour that can be understood in a two-leg spin ladder model
with ferromagnetic legs and antiferromagnetic rungs; the spin gap constitutes about 450 K. Besides,
stable room-temperature ferromagnetism is observed in C
(x < 1) samples: the crossover to a three-
dimensional magnetic behaviour is due to the onset of interlayer interactions. Similarly prepared
(x ≈ 1) samples demonstrate features of two-dimensional magnetism without signs of high-
temperature magnetic ordering, but with transition to a superparamagnetic state below 40 K instead.
The magnetism of the Tabby graphene is stable until 520 K, which is the temperature of the structural
reconstruction of uorinated graphite.
Magnetism in restricted dimensions can be studied in real bulk crystals if the exchange interactions are much
stronger in one or two spatial directions than in the remaining ones
. us, low dimension magnets have the
advantage of bulk materials in providing sucient intensity for experiments investigating the thermodynamic
and spectroscopic characterization of magnetism. Most studies of low dimensional magnetism concentrate on
molecular magnets based on organic radicals (see e.g.
) or Cu and Ni compounds which have spins ½ or 1,
. We have recently synthesized a novel graphene derivative decorated by monoatomic uorine
chains running in crystallographic directions, and have observed clear signs of one-dimensional-like magnetism
in this two-dimensional material
. Nanoscale magnetic activity of pure graphene is controlled by the edge geom-
etry. In the present study, graphene uorination, instead of breaking of the carbon-carbon bonds, is used as an
ecient approach to generate edges and, therefore, correlated magnetic states in this material. e uorine chain
running in zigzag direction induces strong spin polarization with a mixed ferro-antiferro-magnetic coupling
between locally emerged magnetic moments.
A distinctive characteristic of the novel derivative is that the interfaces form Tabby stripes. Tabby is a pattern
of a cat’s coat with tiger stripes and leopard spots. Ideally, if the sp
interfaces were parallel and evenly spaced
lines, they would form embedded graphene nanoribbons. e stoichiometry C
F yields a 3-carbon atom wide
F is a 2-atom wide one, and C
F produces monoatomic chains (Fig.1a). However, this ideal pic-
ture is only partially applicable, because the stripes run in all crystallographic directions (Fig.1b). Still, the Tabby
graphene is a unique derivative because the retention of the π-electron system results in dierent electronic
properties of the Tabby graphene compared to fully functionalized graphene derivatives, which are insulators.
e Tabby graphene contains conned islands of the π-electron system, it is semiconducting with the band gap
2–2.5 eV, and colour dependent on the C/F ratio
. e most distinct feature is that the Tabby graphene contains up
Lappeenranta University of Technology, Lappeenranta, 53851, Finland.
Ioe Institute, St. Petersburg, 194021,
Ben-Gurion University of the Negev, Be’er-Sheva, 8410501, Israel.
St. Petersburg State
University, St. Petersburg, 199034, Russian Federation.
Nikolaev Institute of Inorganic Chemistry SB RAS,
Novosibirsk, 630090, Russian Federation.
Novosibirsk State University, Novosibirsk, 630090, Russian Federation.
T. L. Makarova is deceased. Correspondence and requests for materials should be addressed to E.L. (email: Erkki.
Received: 29 June 2017
Accepted: 8 November 2017
Published: xx xx xxxx