Density functional study of twisted graphene $L1_0$-FePd heterogeneous interface

Abstract

We report on the investigation of the atomic-scale structure and electronic properties of graphene(Gr) on the L1 0 -FePd(001) interface using density functional theory. Although such hetero-interfaces have been experimentally synthesized, due to the significant lattice symmetry mismatch between the graphene and tetragonal alloy surface, a theoretical understanding of the optimal configuration of the carbon atoms is required. In this work, we consider various model structures of twisted and non-twisted FePd(001)/Gr interfaces. To evaluate the stability of our models, we analyzed the adsorption energies per carbon atom by performing structural optimizations, including van der Waals interactions. We found that the most stable structure had an adsorption energy of approximately ≈ −0.109 eV/atom (−10.5 kJ/mol), and the energy barrier of the slide was smaller than 0.05 meV/atom. The FePd-graphene distance was approximately 2 Å, which successfully reproduced the experimental value.