DFT analysis on atomic structure of NiFe/2D materials heterointerface

The applications of two-dimensional materials (2D materials) to tunnel barriers have attracted attention in recent years. To fabricate high-performance devices using 2D materials, it is important to understand the 2D materials/ferromagnetic heterostructure in detail. In this work, to clarify the atomic and electronic structure of 2D materials/ferromagnetic heterostructure, we calculate and analyze NiFe/graphene and NiFe/hBN interface in density functional theory. Computational models are constructed with different conditions, e.g., composition ratios of the metal surface and substrates, and adsorption sites of 2D materials. As a result, atoms of 2D materials located above top site is the most stable. The Ni-rich surface is the preferable for the bare substrate, while the Fe-rich surface is the stable for adsorbed substrate. The reason why the orbital hybridization between Fe and C(N) and the charge transfer from C(N) to Fe occurs. We predict this difference of absorptivity Fe and Ni corresponds to the fabrication process.