Multiferroic Tuning of Magnetic Anisotropy in MnTe2 Monolayer with Li/Na Adsorption

Abstract

Two-dimensional (2D) magnetic materials with tunable magnetic anisotropy energy (MAE) are of great scientific interest and hold immense promise for ultracompact spintronic devices with lower energy consumption and higher storage density. Here, we demonstrate a practical approach for manipulating MAE in layered MnTe₂ through the alkali metal adsorption and ferroelectric (FE) polarization effect. Our results reveal colossal MAE values of up to −12.428 erg/cm² under Li/Na adsorption, accompanied by a spin reorientation and enhanced ferromagnetic (FM) coupling stability. Their negative MAE show a linear enhancement in response to the external strain. Moreover, we find that the FE In₂Se₃ substrate enhances the perpendicular magnetic anisotropy (PMA) of MnTe₂ up to 2.318 erg/cm² depending on the polarization direction. Ferroelectric switching at In₂Se₃-based interfaces could also induce significant MAE changes with the value of 3.838 erg/cm². We elucidate that the underlying mechanisms for these modulations are primarily attributed to alterations in the electron occupancy of interfacial Te₁-derived p_y and p_z states, which affect their competitive spin–orbit coupling (SOC) strengths. These findings highlight the potential of interfacial engineering in tailoring magnetism in 2D materials, opening exciting possibilities for the development of advanced spintronic devices with enhanced functionality.