Ferroelectricity-driven Antiferromagnetism in Ti Intercalated NbS2 Bilayer

Electrical control of antiferromagnetism is highly desirable for realizing low-cost and high-density spintronic devices, yet it remains a major challenge in conventional multiferroics. Here we predict a type-III multiferroics, where antiferromagnetism is driven by ferroelectric (FE) polarization, providing an effective route for controlling antiferromagnetism via electric fields. We reveal that the emergence of electric polarization could greatly change the crystal field splitting, which alters spin occupation states and, thus, induces antiparallel aligned atomic magnetic moments. Using first-principles calculations, we predict ferroelectricity-driven antiferromagnetism in a NbS2 bilayer intercalated by Ti atoms [denoted as Ti(NbS2)2]. The interlayer sliding of the NbS2 bilayer breaks the spatial symmetry and induces an out-of-plane FE polarization. Simultaneously, it changes the crystal field of the intercalated Ti atoms, resulting a transition from nonmagnetic to antiferromagnetic (AFM) phases. The discovery of AFM type-III multiferroics with strong magnetoelectric coupling would open an innovative pathway for realizing next-generation spintronic devices.