First-principles study of magnetic properties of two-dimensional semi conductors ABX$_3$*

We investigate the magnetic properties of monolayers of van der Waals semiconductors ABX$_3$ theoretically. Our density functional theory (DFT) calculations show that these materials display rich magnetic phases. We use wannier analysis to study the competition between the antiferromagnetic direct exchange and the ferromagnetic superexchange, which governs the magnetic ground state. Using the low-energy effective models derived from our DFT results, we discuss the origin of rich magnetic behavior and phase transitions at finite temperature of these materials. We conclude that monolayers ABX$_3$ are suitable candidates for two-dimensional magnetic semiconductors, which have immense applications in next generation spintronics.