Electronic structure and the origin of the high ordering temperature in SrRu2O6

SrRu2O6 is a layered honeycomb lattice material with an extraordinarily high magnetic ordering temperature. We investigated this material using density functional calculations. We find that the energy scales for moment formation and ordering are similar and high. Additionally, we find that the magnetic anisotropy is high and favors moments oriented along the $c$-axis. This provides an explanation for the exceptionally high ordering temperature. Finally, the compound is found to be semiconducting at the bare density functional level, even without magnetic order. Experimental consequences of this scenario for the high ordering temperature are discussed.