Half-metallic behavior and anisotropy of two-dimensional MoSi2N4/ScSi2N4 heterojunction

Abstract

Heterojunctions formed by stacking different two-dimensional monolayer materials typically have tunable electronic properties, which will greatly broaden the application prospects of 2D materials in electron devices. In this paper, the structures, electron properties, and anisotropy of MoSi₂N₄/ScSi₂N₄ heterojunctions formed by stacking MoSi₂N₄ monolayer with semiconductor properties and ScSi₂N₄ monolayer with half-metallic properties have been systematically studied. The results show that Type-Ⅰ configuration has the most stable structure in terms of total energy, binding energy, phonon spectrum and molecular dynamics among the three configurations formed by MoSi₂N₄/ScSi₂N₄ heterojunctions. The MoSi₂N₄/ScSi₂N₄ heterojunction has robust half-metallic behavior and tensile anisotropy at equilibrium. At the same time, MoSi₂N₄/ScSi₂N₄ heterojunction can still maintain stable ferromagnetic and half-metallic properties under large interlayer distance changes. Studies of magnetic anisotropy show that the direction of hard axis for MoSi₂N₄/ScSi₂N₄ heterojunction is perpendicular to the 2D layer plane. The tunable properties of MoSi₂N₄/ScSi₂N₄ heterojunction provides promising exploration for novel 2D materials.