TY - JOUR
T1 - First-principles study of substitutional metal impurities in graphene: structural, electronic and magnetic properties
AU - Santos, Elton
AU - Ayuela, A.
AU - Sánchez-Portal, D.
PY - 2010/5/1
Y1 - 2010/5/1
N2 - We present a theoretical study using density functional calculations of
the structural, electronic and magnetic properties of 3d transition
metal, noble metal and Zn atoms interacting with carbon monovacancies in
graphene. We pay special attention to the electronic and magnetic
properties of these substitutional impurities and find that they can be
fully understood using a simple model based on the hybridization between
the states of the metal atom, particularly the d shell, and the defect
levels associated with an unreconstructed D3h carbon vacancy.
We identify three different regimes associated with the occupation of
different carbon-metal hybridized electronic levels: (i) bonding states
are completely filled for Sc and Ti, and these impurities are
non-magnetic; (ii) the non-bonding d shell is partially occupied for V,
Cr and Mn and, correspondingly, these impurities present large and
localized spin moments; (iii) antibonding states with increasing carbon
character are progressively filled for Co, Ni, the noble metals and Zn.
The spin moments of these impurities oscillate between 0 and
1μB and are increasingly delocalized. The substitutional
Zn suffers a Jahn-Teller-like distortion from the C3v
symmetry and, as a consequence, has a zero spin moment. Fe occupies a
distinct position at the border between regimes (ii) and (iii) and shows
a more complex behavior: while it is non-magnetic at the level of
generalized gradient approximation (GGA) calculations, its spin moment
can be switched on using GGA+U calculations with moderate values of the
U parameter.
AB - We present a theoretical study using density functional calculations of
the structural, electronic and magnetic properties of 3d transition
metal, noble metal and Zn atoms interacting with carbon monovacancies in
graphene. We pay special attention to the electronic and magnetic
properties of these substitutional impurities and find that they can be
fully understood using a simple model based on the hybridization between
the states of the metal atom, particularly the d shell, and the defect
levels associated with an unreconstructed D3h carbon vacancy.
We identify three different regimes associated with the occupation of
different carbon-metal hybridized electronic levels: (i) bonding states
are completely filled for Sc and Ti, and these impurities are
non-magnetic; (ii) the non-bonding d shell is partially occupied for V,
Cr and Mn and, correspondingly, these impurities present large and
localized spin moments; (iii) antibonding states with increasing carbon
character are progressively filled for Co, Ni, the noble metals and Zn.
The spin moments of these impurities oscillate between 0 and
1μB and are increasingly delocalized. The substitutional
Zn suffers a Jahn-Teller-like distortion from the C3v
symmetry and, as a consequence, has a zero spin moment. Fe occupies a
distinct position at the border between regimes (ii) and (iii) and shows
a more complex behavior: while it is non-magnetic at the level of
generalized gradient approximation (GGA) calculations, its spin moment
can be switched on using GGA+U calculations with moderate values of the
U parameter.
UR - https://pure.qub.ac.uk/en/publications/firstprinciples-study-of-substitutional-metal-impurities-in-graphene-structural-electronic-and-magnetic-properties(60b9e609-23da-49ee-a737-5119d190aa91).html
U2 - 10.1088/1367-2630/12/5/053012
DO - 10.1088/1367-2630/12/5/053012
M3 - Article
SN - 1367-2630
JO - New Journal of Physics
JF - New Journal of Physics
ER -