The static and dynamic magnetic properties of monolayer iron dioxide and iron dichalcogenides

Abstract

The electronic structures, and static and dynamic magnetic properties of monolayer iron dioxide and iron dichalcogenides (FeX₂ (X = O, S, Se, Te)) are investigated using first-principle calculations in conjunction with Monte Carlo (MC) simulation and atomic spin dynamics (ASD) simulation. In this rarely studied family of monolayer binary compounds a variety of possible phases are discovered, including narrow bandgap a semiconductor (FeO₂), half-metal (FeS₂) and metal (FeSe₂ and FeTe₂), and all the ground states are ferromagnetic (FM). Based on the magnetic exchange interactions, the temperature dependence of the average magnetic moment per unit cell and magnetic susceptibility of monolayer FeX₂ are predicted. The Curie temperatures (T_Cs) are estimated and magnon dispersions as a function of temperature are demonstrated, revealing a new family of pristine monolayers with transition temperatures (96–168 K) above the liquid-nitrogen temperature.