Adatom bond-induced geometric and electronic properties of passivated armchair graphene nanoribbons

Electronic, magnetic, and optical properties of Np and Pu decorated armchair graphene nanoribbons: a DFT study

We employed Density Functional Theory (DFT) to investigate the electronic, magnetic, and optical characteristics of armchair graphene nanoribbons (AGNRs) decorated with neptunium (Np) and plutonium (Pu). Our analysis delves deeply into the intricate orbital hybridizations associated with C-Np, C-Pu, C-C, Np-Np, and Pu-Pu chemical bonds. Through this approach, we explore the electronic band structure, band-decomposed charge densities, spin-charge distributions, and Van Hove singularities in the density of states. Furthermore, our examination successfully correlates optical excitation with electronic band energy. Our results indicated that these rare-earth atoms are strongly bound to the edge structure of AGNRs, significantly altering their electronic, magnetic, and optical properties. Theoretical exploration not only reveals the intriguing physical and chemical properties of rare-earth (Np/Pu) decorated AGNRs but also presents a practical pathway for synthesizing novel materials.

Fluorination-enriched electronic and magnetic properties in graphene nanoribbons

The feature-rich electronic and magnetic properties of fluorine-doped graphene nanoribbons are investigated by the first-principles calculations. They arise from the cooperative or competitive relations among the significant chemical bonds, finite-size quantum confinement and edge structure. There exist C-C, C-F, and F-F bonds with multi-orbital hybridizations. Fluorine adatoms can create p-type metals or concentration- and distribution-dependent semiconductors, depending on whether the π bonding is seriously suppressed by the top-site chemical bonding. Furthermore, five kinds of spin-dependent electronic and magnetic properties cover the non-magnetic and ferromagnetic metals, non-magnetic semiconductors, and anti-ferromagnetic semiconductors with/without spin splitting. The diverse essential properties are clearly revealed in the spatial charge distribution, spin density, and orbital-projected density of states.

Alkali-created rich properties in grapheme nanoribbons: Chemical bondings

The alkali-adsorbed graphene nanoribbons exhibit the feature-rich electronic and magnetic properties. From the first-principles calculations, there are only few adatom-dominated conduction bands, and the other conduction and valence bands are caused by carbon atoms. A lot of free electrons are revealed in the occupied alkali- and carbon-dependent conduction bands. Energy bands are sensitive to the concentration, distribution and kind of adatom and the edge structure, while the total linear free carrier density only relies on the first one. These mainly arise from a single s − 2p_z orbital hybridization in the adatom-carbon bond. Specifically, zigzag systems can present the anti-ferromagnetic ordering across two edges, ferromagnetic ordering along one edge and non-magnetism, being reflected in the edge-localized energy bands with or without spin splitting. The diverse energy dispersions contribute many special peaks in density of states. The critical chemical bonding and the distinct spin configuration could be verified from the experimental measurements.

Anomalous twisting strength of tilt grain boundaries in armchair graphene nanoribbons

The critical instability twist rate of graphene nanoribbons can be improved by grain boundaries.