Intrinsic multiferroic MnOF monolayer with room-temperature ferromagnetism

Two-dimensional (2D) multiferroic materials have generated substantial interest owing to the interplay between various ferroic states and the potential applications in miniaturized electronic devices. Using first-principles calculations, we report a ferromagnetic, ferroelectric, and ferroelastic MnOF monolayer, which is an indirect semiconductor with a band gap of 1.8 eV. The Cuire temperature is predicted to be 420 K based on the Monte Carlo simulation of Heisenberg model. The magnetic easy-axis prefers to align along c-axis. Moreover, it shows excellent ferroelectricity with a switchable spontaneous polarization of 7.5 μC/cm2. Meanwhile, MnOF monolayer also habors ferroealsticity with a large reversible strain of 21.4% and a moderate switching energy barrier, which can effectively switchferroelectric polarization direction. MnOF monolayer thus offers a perfect platform for studying the 2D multiferroic coupling effects.