Intrinsic ferromagnetism in atomically thin two-dimensional organic-inorganic van der Waals crystals

Following the recent excitement in two-dimensional (2D) magnetism, we propose a yet-unexplored class of 2D ferromagnets derived out of Cr-based organic-inorganic layered compounds. Our density functional study in conjunction with model calculation establishes that assisted by the finite magnetocrystalline anisotropy, the ferromagnetic long-range order survives at the atomically thin limit consisting of monolayer of Cr spins, with calculated magnetic transition temperatures of ∼10-20-K. Upon application of modest magnetic field, the magnetic transition temperature is found to increase substantially. The calculated exfoliation energy suggests that synthesis of these 2D compounds through mechanical exfoliation is possible, which should encourage future experiments on this proposed class of 2D magnets.