TY - JOUR
T1 - Diversified phenomena in metal-and transition-metal-adsorbed graphene nanoribbons
AU - Lin, Shih Yang
AU - Tran, Ngoc Thanh Thuy
AU - Fa-Lin, Ming
N1 - Funding Information:
In general, the metal (Bi, Al)-and transition metal (Ti, Fe, Co, Ni)-adsorbed GNRs can greatly induce metallic behaviors. They clearly display important differences in their fundamental properties. The Al and Ti/Fe/Co/Ni guest atoms exhibit the hollow-site optimal positions, while the former might have the y-direction shifts, especially for the non-symmetric distributions. The similar shifts are revealed in the deviated bridge-site Bi adsorptions. The adatom chemisorptions are relatively easily observed in the Ti systems with the largest binding energies. Energy bands, which cross the Fermi level, mainly arise from carbon atoms or metal atoms for Al-adsorbed systems or the Bi/Ti/Fe/Co/Ni ones, respectively. Three types of observable Bi–C bondings, 6pz-2pz, 6px-2pz, and 6py-2pz, are characterized by the charge distributions and DOSs except for the symmetric single-adatom adsorptions. The important (6px, 6py, 6pz)-(6px, 6py, 6pz) orbital hybridizations in Bi-Bi bonds are responsible for the Bi-induced low-lying energy bands. For Al adsorptions, there exist the adatom-dominated valence bands at Ev ∼3 eV and the partial adatom contributions to the conduction bands, being consistent with the 3pz-2pz and (3px+3py)-2pz orbital hybridizations in Al–C bonds. This feature is also supported by the spatial charge distributions and DOSs. The multi-orbital hybridizations between Ti/Fe/Co/Ni-C bonds are very complicated, in which five orbitals of the adatom, (dxy, dxz, dyz, dz2, dx2−y2), have strong interactions with 2pz orbitals of carbons. Such orbitals also take part in the adatom-adatom chemical bondings.
Funding Information:
Funding: This research was funded by the Ministry of Science and Technology Grant Number MOST 108-2112-M-006-022-MY3 in Taiwan.
Funding Information:
Acknowledgments: This work was supported by the Taiwan Ministry of Science and Technology (MOST) under the project 108-2112-M-006-022-MY3 and the Hierarchical Green-Energy Materials (Hi-GEM) Research Center, National Cheng Kung University, Taiwan.
Publisher Copyright:
© 2021 by the authors. Licensee MDPI, Basel, Switzerland.
PY - 2021/3
Y1 - 2021/3
N2 - Adatom-adsorbed graphene nanoribbons (GNRs) have gained much attention owing to the tunable electronic and magnetic properties. The metal (Bi, Al)/transition metal (Ti, Fe, Co, Ni) atoms could provide various outermost orbitals for the multi-orbital hybridizations with the out-of-plane π bondings on the carbon honeycomb lattice, which dominate the fundamental properties of chemisorption systems. In this study, the significant similarities and differences among Bi-/Al-/Ti-/Fe-/Co-/Ni-adsorbed GNRs are thoroughly investigated by using the first-principles calculations. The main characterizations include the adsorption sites, bond lengths, stability, band structures, charge density distributions, spin-and orbital-projected density of states, and magnetic configurations. Furthermore, there exists a transformation from finite gap semiconducting to metallic behaviors, accompanied by the nonmagnetism, antiferromagnetism, or ferromagnetism. They arise from the cooperative or competitive relations among the significant chemical bonds, finite-size quantum confinement, edge structure, and spin-dependent many-body effects. The proposed theoretical framework could be further improved and generalized to explore other emergent 1D and 2D materials.
AB - Adatom-adsorbed graphene nanoribbons (GNRs) have gained much attention owing to the tunable electronic and magnetic properties. The metal (Bi, Al)/transition metal (Ti, Fe, Co, Ni) atoms could provide various outermost orbitals for the multi-orbital hybridizations with the out-of-plane π bondings on the carbon honeycomb lattice, which dominate the fundamental properties of chemisorption systems. In this study, the significant similarities and differences among Bi-/Al-/Ti-/Fe-/Co-/Ni-adsorbed GNRs are thoroughly investigated by using the first-principles calculations. The main characterizations include the adsorption sites, bond lengths, stability, band structures, charge density distributions, spin-and orbital-projected density of states, and magnetic configurations. Furthermore, there exists a transformation from finite gap semiconducting to metallic behaviors, accompanied by the nonmagnetism, antiferromagnetism, or ferromagnetism. They arise from the cooperative or competitive relations among the significant chemical bonds, finite-size quantum confinement, edge structure, and spin-dependent many-body effects. The proposed theoretical framework could be further improved and generalized to explore other emergent 1D and 2D materials.
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U2 - 10.3390/nano11030630
DO - 10.3390/nano11030630
M3 - Article
AN - SCOPUS:85101813021
SN - 2079-4991
VL - 11
SP - 1
EP - 21
JO - Nanomaterials
JF - Nanomaterials
IS - 3
M1 - 630
ER -