Ab Initio Study of Structural, Electronic, and Magnetic Properties of Transition Metal Atoms Intercalated AA-Stacked Bilayer Graphene

Abstract

The structural, electronic, and magnetic properties of transition metal atoms intercalated bilayer graphene, [GTMG]x/y, (x, y is integer, TM = Ti, Cr, Mn, Fe) with different TM/carbon hexagons ratios and insertion patterns, are systematically studied by density functional theory calculations. All the studied systems are thermodynamically stable and competitive ionic–covalent bonding characters are dominated in the TM–graphene interaction. Most studied systems are ferromagnetic; particularly, [GCrG]1:18, [GCrG]1:9, [GFeG]1:6(1), and [GTMG]1:6(2) (TM = Cr, Mn, Fe) exhibit large magnetic moment of 4.43, 5.60, 7.02, 10.85, 9.04, and 5.19 μB per unit cell, respectively. In contrast, [GCrG]1:8 and [GFeG]1:8 are ferrimagnetic, while eight other [GTMG]x/y are nonmagnetic. Moreover, five intercalation nanostructures of [GTMG]1:18 (TM = Ti, Mn), [GTMG]1:9 (TM = Ti, Mn) and [GTiG]1:6 are semiconductors with the gaps of 0.141/0.824 eV, 0.413/0.668 eV, and 0.087 eV, respectively. Comparison on different isomers with s...