Study on structural, electronic and magnetic properties of Sn atom adsorbed on defective graphene by first-principle calculations

The structural, electronic and magnetic properties of the Sn atom adsorption on pristine and defective graphene are comparatively studied by first-principle calculations with the generalized gradient approximation and local density approximation. For Sn atom adsorbed on pristine graphene, minimal adsorption energies and small charge transfer denotes the ionic bonding. The adsorption tune the Fermi level up but the unique Dirac point structure remains intact. Also the semiconductor graphene with zero bandgap becomes metallic and obtains a magnetic moment. For Sn atom adsorbed on defective graphene, the large adsorption energies and the bond lengths which smaller than the sum of covalent bond length indicate that the bonding is covalent bonding. Moderate and no bandgap were observed at the Fermi level in the Sn atom adsorbed on single vacancy and double vacancies graphene system, respectively. The zero bandgap semiconductor character of pristine graphene is dramatically changed due to the substitution of Sn. Sn atom adsorbed on defective graphene show nonmagnetic characters as pristine graphene.