Nano-modulated Electronic States Induced by Structural Strain in a Moiré Pattern on an Iron-nitride Atomic Layer

Abstract

Strain-induced modulation of electronic states in a Moiré pattern on a hexagonal-type FeN monoatomic layer has been studied using scanning tunneling microscopy and spectroscopy. The hexagonal FeN film is stabilized by a strong Fe-N bond even on the square Cu(001) substrate and shows a strip structure comprising regular and deformed hexagonal lattices. By analyzing the atomically resolved images, we have found that the lattice is periodically deformed along a hypothetical Moiré pattern between a perfect hexagonal lattice and the square Cu(001) lattice. Moreover, dI/dV spectra exhibit spatial change of the unoccupied local density of states, which is attributed to an energy shift of the antibonding states due to the periodic compressive lattice strain.