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

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 MnTe through the alkali metal adsorption and ferroelectric (FE) polarization effect. Our results reveal colossal MAE values of up to -12.428 erg/cm 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 InSe substrate enhances the perpendicular magnetic anisotropy (PMA) of MnTe up to 2.318 erg/cm depending on the polarization direction. Ferroelectric switching at InSe-based interfaces could also induce significant MAE changes with the value of 3.838 erg/cm. We elucidate that the underlying mechanisms for these modulations are primarily attributed to alterations in the electron occupancy of interfacial Te-derived and 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.