Quasi-freestanding graphene on Ni(111) by Cs intercalation

Abstract

A possible approach to achieve quasi-freestanding graphene on a substrate for technological purpose is the intercalation of alkali metal atoms. Cs intercalation between graphene and Ni(111) therefore is investigated using density functional theory, incorporating van der Waals corrections. It is known that direct contact between graphene and Ni(111) perturbs the Dirac states. We find that Cs intercalation restores the linear dispersion characteristic of Dirac fermions, which agrees with experiments, but the Dirac cone is shifted to lower energy, i.e., the graphene sheet is n-doped. Cs intercalation therefore decouples the graphene sheet from the substrate except for a charge transfer. On the other hand, the spin polarization of Ni(111) does not extend through the intercalated atoms to the graphene sheet, for which we find virtually spin-degeneracy.

The electron–phonon coupling constant for single-layer graphene on metal substrates determined from He atom scattering

“…24 Therefore they should all act as acceptors. Angle resolved photoelectron scattering (ARPES) data show, however, that Ir(111) (H. Vita et al), 25 Pt(111) (P. Sutter et al), 26 and Ni(111) (A. Alattis et al), 27 act as acceptors with respect to graphene, whereas Ru(0001) (Katsiev et al), 28 and Cu(111) (Walter et al) 29 act as donors. Former HAS studies on Gr/Ru(0001) have provided evidence that the tail of the substrate electron charge density actually extends beyond the graphene.…”

Modulating the electronic and magnetic properties of graphene

“…52 Its use is limited due to alteration of the graphene Dirac cone during growth. However, the linear dispersion of pristine graphene is preserved by intercalation of alkali metals 53 and noble metals 54 between graphene and its Ni (111) substrate. The absence of p surface plasmon excitation indicated that the graphene band structure is inuenced by interactions with the Ni substrate.…”

Adsorbed or intercalated: Na on graphene/Ir(111)

“…Coupling to the surface is particularly strong for graphene on Ni [23], Co [24], and Ru [25]. Intercalation of AM can lead to a large increase in the graphene/substrate separation with the effect of graphene decoupling from the substrate accompanied by the recovery of the π band's dispersion [2,[26][27][28].…”