The ultra-wide single spin states are of importance for ideal magnetic storage materials and spin injection sources. Here, a new type of CrOX (X= Cr, Br, I) monolayer has been revealed. We find that the basic constructive units for such new monolayers are four-coordinated, almost never being reported until now. More interestingly, they are half-metals and have an ultra-wide single spin channel in their electronic band structures. Monte Carlo simulations show that the Curie temperatures of three monolayers are relatively low, however they can be enhanced to exceed the liquid nitrogen temperatur...
