Data di Pubblicazione:
2012
Citazione:
Novel substrates for Helium adsorption : Graphane
and Graphene–Fluoride / L Reatto, M Nava, D E Galli, C Billman, J O Sofo, and M W Cole. - In: JOURNAL OF PHYSICS. CONFERENCE SERIES. - ISSN 1742-6588. - 400:Part.1(2012), pp. 012010.1-012010.6. [10.1088/1742-6596/400/1/012010]
Abstract:
The discovery of fullerenes has stimulated extensive exploration of the resulting
behavior of adsorbed films. Our study addresses the planar substrates graphene–fluoride (GF)
and graphane (GH) in comparison to graphene. We present initial results concerning the
potential energy, energy bands and low density behavior of 4He and 3He films on such different
surfaces. For example, while graphene presents an adsorption potential that is qualitatively
similar to that on graphite, GF and GH yield potentials with different symmetry, a number of
adsorption sites double that on graphene/graphite and a larger corrugation for the adatom. In
the case of GF, the lowest energy band width is similar to that on graphite but the He atom
has a significantly larger effective mass and the adsorption energy is about three time that on
graphite. Implications concerning the monolayer phase diagram of 4He are explored with the
exact path integral ground state method. A commensurate ordered state similar to the p3×
p3
R30o state on graphite is found the be unstable both on GF and on GH. The ground states of
submonolayer 4He on both GF and GH are superfluids with a Bose Einstein condensate fraction
of about 10%.
Tipologia IRIS:
01 - Articolo su periodico
Elenco autori:
L. Reatto, M. Nava, D. E Galli, C. Billman, J.O. Sofo, M.W. Cole
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