Mechanical properties and magnetic and electronic properties tuned via strain in two-dimensional non-van der Waals hematene

Abstract

Two-dimensional (2D) non-van der Waals hematene has increasingly attracted attention in the applications of photocatalysis, spintronic devices, and magnetic storage media. Mechanical properties as well as magnetic and electronic properties tuned via strain in two-dimensional non-van der Waals Fe-terminated (hematene-1) and O-terminated hematene (hematene-2) have been systematically studied using the first principles density functional theory. The stress-strain relationships for 2D hematene-1 and hematene-2 demonstrate the influence of biaxial strain is larger than that of uniaxial strain, and under uniaxial strain, the stress-strain relationships transform from the isotropic and linear elastic behavior under small strain to the anisotropic and nonlinear response under large strain. For hematene-1 under uniaxial and biaxial strain and hematene-2 under biaxial strain, the magnetic moments of Fe1 and Fe2 atoms increase monotonically with applied strain, while for hematene-2 under uniaxial strain, the magnetic moment of Fe1 atom first decreases and then increases with applied strain, and the case is opposite for Fe2 atom. For hematene-1, the band gap decreases with increasing strain from −10% to 7%, while for hematene-2 under uniaxial strain, the spin up band gap decreases with increasing strain, and the case is opposite for the spin down band gap. The present work not only provides a basic understanding of the mechanical properties of 2D hematene but also demonstrates its magnetic and electronic properties tuned by strain engineering for the potential possibility in both spintronic and catalytic applications.