Design of half-metallic properties induced by 2p impurities in ZnO nanosheet

We perform first-principles study on the electronic and magnetic properties of X-doped (X=Be, B, C, N) graphene-like ZnO nanosheet (NS). When one oxygen is substituted by X atom in ZnONS, X-induced spin polarizations led to transition from the semiconducting to half-metallic properties, with magnetic moments of 2.0, 1.0, 2.0, and 1.0 μB per Be, B, C, and N dopant, respectively. The local magnetic moments are found to equal to unpaired electrons in the 2p spin states of the doping X atoms. While two oxygen atoms are substituted by X in ZnONS, the formation energy analysis indicates that X ions have a clear clustering tendency. Depending on distance between two X dopants, the ferromagnetic, antiferromagnetic or nonmagnetic states are all found in X-doped ZnONSs. More interestingly, for C and N doped cases, the half-metallic properties are robust independent on the doping concentrations, while Be or B doped systems would result in half-metallic to magnetic state transition as the doping concentrations increase.