TY  - JOUR
AU  - Stavrić, Srđan
AU  - del Puppo, Simone
AU  - Šljivančanin, Željko
AU  - Peressi, Maria
PY  - 2021
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/9561
AB  - Recent experiments indicate that the reactivity of metal surfaces changes profoundly when they are covered with two-dimensional (2D) materials. Nickel, the widespread catalyst choice for graphene (G) growth, exhibits complex surface restructuring even after the G sheet is fully grown. In particular, due to excess carbon segregation from bulk nickel to surface upon cooling, a nickel carbide (Ni2C) phase is detected under rotated graphene (RG) but not under epitaxial graphene (EG). Motivated by this experimental evidence, we construct different G/Ni(111) interface models accounting for the two types of G domains. Then, by applying density functional theory, we illuminate the microscopic mechanisms governing the structural changes of nickel surface induced by carbon segregation. A high concentration of subsurface carbon reduces the structural stability of Ni(111) surface and gives rise to the formation of thermodynamically advantageous Ni2C monolayer. We show the restructuring of the nickel surface under RG cover and reveal the essential role of G rotation in enabling high density of favorable C binding sites in the Ni(111) subsurface. As opposed to RG, the EG cover locks the majority of favorable C binding sites preventing the build-up of subsurface carbon density to a phase transition threshold. Therefore we confirm that the conversion of C-rich Ni surface to Ni2C takes place exclusively under RG cover, in line with the strong experimental evidence. © 2021 American Physical Society.
T2  - Physical Review Materials
T1  - First-principles study of nickel reactivity under two-dimensional cover: Ni2 C formation at rotated graphene/Ni(111) interface
VL  - 5
IS  - 1
SP  - 014003
DO  - 10.1103/PhysRevMaterials.5.014003
ER  - 

@article{
author = "Stavrić, Srđan and del Puppo, Simone and Šljivančanin, Željko and Peressi, Maria",
year = "2021",
abstract = "Recent experiments indicate that the reactivity of metal surfaces changes profoundly when they are covered with two-dimensional (2D) materials. Nickel, the widespread catalyst choice for graphene (G) growth, exhibits complex surface restructuring even after the G sheet is fully grown. In particular, due to excess carbon segregation from bulk nickel to surface upon cooling, a nickel carbide (Ni2C) phase is detected under rotated graphene (RG) but not under epitaxial graphene (EG). Motivated by this experimental evidence, we construct different G/Ni(111) interface models accounting for the two types of G domains. Then, by applying density functional theory, we illuminate the microscopic mechanisms governing the structural changes of nickel surface induced by carbon segregation. A high concentration of subsurface carbon reduces the structural stability of Ni(111) surface and gives rise to the formation of thermodynamically advantageous Ni2C monolayer. We show the restructuring of the nickel surface under RG cover and reveal the essential role of G rotation in enabling high density of favorable C binding sites in the Ni(111) subsurface. As opposed to RG, the EG cover locks the majority of favorable C binding sites preventing the build-up of subsurface carbon density to a phase transition threshold. Therefore we confirm that the conversion of C-rich Ni surface to Ni2C takes place exclusively under RG cover, in line with the strong experimental evidence. © 2021 American Physical Society.",
journal = "Physical Review Materials",
title = "First-principles study of nickel reactivity under two-dimensional cover: Ni2 C formation at rotated graphene/Ni(111) interface",
volume = "5",
number = "1",
pages = "014003",
doi = "10.1103/PhysRevMaterials.5.014003"
}

Stavrić, S., del Puppo, S., Šljivančanin, Ž.,& Peressi, M.. (2021). First-principles study of nickel reactivity under two-dimensional cover: Ni2 C formation at rotated graphene/Ni(111) interface. in Physical Review Materials, 5(1), 014003.
https://doi.org/10.1103/PhysRevMaterials.5.014003

Stavrić S, del Puppo S, Šljivančanin Ž, Peressi M. First-principles study of nickel reactivity under two-dimensional cover: Ni2 C formation at rotated graphene/Ni(111) interface. in Physical Review Materials. 2021;5(1):014003.
doi:10.1103/PhysRevMaterials.5.014003 .

Stavrić, Srđan, del Puppo, Simone, Šljivančanin, Željko, Peressi, Maria, "First-principles study of nickel reactivity under two-dimensional cover: Ni2 C formation at rotated graphene/Ni(111) interface" in Physical Review Materials, 5, no. 1 (2021):014003,
https://doi.org/10.1103/PhysRevMaterials.5.014003 . .