Spin-driven multiferroics in non–van der Waals Cr2S3

Multiferroics exhibiting simultaneous magnetic and ferroelectric orders constitute essential systems for realizing magnetoelectric coupling, thereby presenting considerable promise for technological applications. However, the development of multiferroics faces a persistent challenge: achieving the coexistence of robust magnetoelectric coupling and pronounced ferroelectric polarization. In this study, we demonstrate the emergence of spin-driven ferroelectricity in $\mathrm{C}{\mathrm{r}}_{2}{\mathrm{S}}_{3}$ through first-principles calculations. The system exhibits out-of-plane polarization significantly exceeding that of most conventional type-II multiferroics, and features a unique pathway for ferroelectric switching through spin rotation. Furthermore, two-dimensional $\mathrm{C}{\mathrm{r}}_{2}{\mathrm{S}}_{3}$ demonstrates half-metallic behavior and maintains spin-induced ferroelectric polarization. This discovery marks a substantial advancement in the design of multiferroics.