Intercalation of Mn in graphene/Cu(111) interface: insights to the electronic and magnetic properties from theory

Abstract

The effect of Mn intercalation on the atomic, electronic and magnetic structure of the graphene/Cu(111) interface is studied using state-of-the-art density functional theory calculations. Different structural models of the graphene–Mn–Cu(111) interface are investigated. While a Mn monolayer placed between graphene and Cu(111) (an unfavorable configuration) yields massive rearrangement of the graphene-derived $$\pi $$ π bands in the vicinity of the Fermi level, the possible formation of a $$\hbox {Cu}_2$$ Cu 2 Mn alloy at the interface (a favorable configuration) preserves the linear dispersion for these bands. The deep analysis of the electronic states around the Dirac point for the graphene/$$\hbox {Cu}_2$$ Cu 2 Mn/Cu(111) system allows to discriminate between contributions from three carbon sublattices of a graphene layer in this system and to explain the bands’ as well as spins’ topology of the electronic states around the Fermi level.

Thermal Annealing of Graphene Implanted with Mn at Ultralow Energies: From Disordered and Contaminated to Nearly Pristine Graphene

“…However, because various factors that influence the Fermi level in graphene change upon annealing in UHV (graphene defects, contaminants/impurities, and nonsubstitutional Mn configurations), it is not possible to establish the origin of this shift based on the present data. We can nevertheless note that an intercalated Mn layer, between graphene and Cu(111), has been predicted to destroy the Dirac cone, while a subsurface alloy preserves it . The conversion from intercalated Mn to subsurface alloy (indicated by our XPS and STM data, as discussed above) may therefore also contribute, together with the disorder annealing, to the improvement in the spectral features observed in the ARPES data from 425 to 700 °C annealing in UHV.…”

“…We can nevertheless note that an intercalated Mn layer, between graphene and Cu(111), has been predicted to destroy the Dirac cone, while a subsurface alloy preserves it. 48 The conversion from intercalated Mn to subsurface alloy (indicated by our XPS and STM data, as discussed above) may therefore also contribute, together with the disorder annealing, to the improvement in the spectral features observed in the ARPES data from 425 to 700 °C annealing in UHV.…”

“…The formation of such a subsurface alloy has indeed been predicted to be thermodynamically favorable compared to the intercalated Mn layer configuration in graphene on Cu(111). 48 The diffusion of Mn into Cu, toward the alloy formation, is likely to be associated with a high diffusion barrier, requiring relatively high annealing temperatures (above 425 °C). Although the Mn atoms remain in the sample, their apparent intensity decreases in our XPS data because of inelastic scattering of the photoelectrons, as the Mn atoms diffuse into Cu with increasing annealing temperature (diffusion of a larger fraction of the Mn atoms and deeper into the Cu layer).…”

“…Subsequently, at higher annealing temperatures, intercalated Mn diffuses into the Cu layer, forming a subsurface alloy (Figure c). The formation of such a subsurface alloy has indeed been predicted to be thermodynamically favorable compared to the intercalated Mn layer configuration in graphene on Cu(111) . The diffusion of Mn into Cu, toward the alloy formation, is likely to be associated with a high diffusion barrier, requiring relatively high annealing temperatures (above 425 °C).…”

Electronic and Magnetic Properties of the Graphene/Y/Co(0001) Interfaces: Insights from the Density Functional Theory Analysis

“…The electronic structure of the gr/FM interface can be further modified via intercalation of different species with the aim to prepare different graphene-based heterostructures. Here, e.g., the intercalation of Fe leads to an increase of the induced magnetic moment in graphene; , the intercalation of noble metals and halogens decouples graphene from the FM material with a controllable modification of the graphene band structure around the Dirac point. − The intercalation of oxygen in gr/Ni and gr/Co interfaces leads to the formation of thin layers of antiferromagnetic (AFM) metal oxides and the resulting epitaxial graphene-protected AFM/FM systems, which can be used in future spintronics applications. − Moreover, the insertion of other magnetic atoms with open d-shells into the gr/metal interface might lead to the formation of ordered gr/FM-alloy systems with interesting properties. − Therefore, the studies of such gr/FM hybrid systems have a huge implications from both the basic scientific and technological standpoints.…”