Hybrid density-functional calculation of the electronic and magnetic structures of tetragonal CuO

Abstract

The electronic and magnetic properties of newly synthesized tetragonal CuO with c/a >1 is calculated by means of hybrid density functional theory. We predict that this tetragonal phase orders antiferromagnetically and has an exceptionally high Ne�el temperature TN � 800 K, which makes it an ideal candidate for doping experiments and a potential parent of new cuprates. The electronic structure is characterized by a charge transfer gap of 2.7 eV, whereas the magnetic properties are dominated by the antiferromagnetic Cu-O-Cu interactions along the nearest-neighbour [100] direction. In addition, we predict the second tetragonal CuO phase with a c/a ratio <1 with a different antiferromagnetic ordering and a similar high TN. We suggest that this new phase could be synthesized by epitaxial growth.